Perfect Weather on the Net

ctwxman writes "Here in the East, we're having a heck of a weekend. The snow has been flying, accompanied by wind, accompanied by people on TV saying, 'stay home.' I'm one of those people. I forecast the weather for a living. It's a great job... a magnificent physics puzzle, solvable with high level math and some acquired skill. And, there's a new puzzle every day, tenuously linked to the one you solved yesterday. When I started doing this over 20 years ago, the data to accomplish the task was tough to come by. I remember how excited I got when I first was able to get data at 300 baud on a request/reply basis (I guess we call that interactive now). Now, nearly everything you need to forecast the weather is here, on the net. Yes, there are a zillion sites that already have the finished forecast, but this is Slashdot. We don't need no stinkin' forecasters!" Read on for ctwxman's notes on do-it-yourself weather forecasting.

ctwxman continues:

I always like to start at NCEP (National Centers for Environmental Prediction) for a look at the dynamic models. Each is run using somewhat different equations, making them often come up with different, quite contrary solutions. Some of these models, like the GFS are worldwide in their coverage and forecast out an amazing 16 days (note: the word accurately was not used in the last sentence). Once the dynamic models are through, we can massage them against past performance under similar circumstances at specific places. These are the statistical models, referred to as MOS (Model Output Statistic) models. Again, there are somewhat different solutions from different models. If none of these work for you, run your own. There are programs available to allow you to run your own model, specifying the domain, grid spacing, time interval, etc. The most commonly used research model of this type is the MM5, produced at Penn State University. Run it on your PC! Of course, it's freely available and supported. Sometimes, the data you want already exists, but not in the form you'd like to see it. That's where software like GrADS comes in. Put out by the Institute of Global Atmosphere and Society's Center for Ocean-Land-Atmosphere Studies, GrADS claims to be an 'interactive desktop tool that is used for easy access, manipulation, and visualization of earth science data.' I agree with all except 'easy.' I run a version of GrADS on my server in order to produce localized forecast graphics like this that wouldn't otherwise be available. Yes, looking at satellite imagery and radar is a lot of fun... but the real fun is knowing what will be there before you look. And, astoundingly enough, we are significantly more accurate (and I get assaulted significantly less often at the grocery store) than even a few years ago.

Comments

Run your OWN weather station

[caferace]

I bet I'm not alone doing this. Decent weather stations are cheap, and it's simple enough to hook it into your box and keep statistical models on a running basis. Using wx200d and an Oregon Scientific WM-918 (sold under other names as well) is a great solution for less than USD $200.

Granted, it's not true forecasting, but you can easily add your data to aggregate with other users at Weather Underground and pull radar data from just about anywhere.

Me? I just like to know what's happening NOW, but it's also pretty handy to know what the temp is in your home "server room".

Tying all this historical data back into longer range forecasts would be fun. I've found TV forecasting to be pretty stale and inaccurate. How many of them have real meteorological degrees anyway?

Re:Run your OWN weather station

[Anonymous Coward]

If I want to know what's happening now,

I LOOK OUT THE DAMN WINDOW YOU GEEK.

Re:Run your OWN weather station

[caferace]

LOOK OUT THE DAMN WINDOW YOU GEEK

Dear AnonTard,

I know reading may be difficult for you, but what you may not understand is a home weather station tied into your computer and the Magic InterWeb allows you to monitor the weather at home remotely. Even if you're 10,000 miles away. Wow.

This can be handy if your AC breaks (That means Air Conditioning, not you) and you need to have someone repair it while you're at a distant location.

Re:Run your OWN weather station

[The Dobber]

How many of them have real meteorological degrees anyway?

I ain't watchin the Weather Bunnies cause of thier metrological (sp) ability.

Anyone ever note the frequency of pregnancies on the Weather Channel. Place must be a god damn rabbit warren.

Re:Run your OWN weather station

[barzok]

How many of them have real meteorological degrees anyway?

Ever notice how some of the TV weather people are called "weathermen" while others are called "meteorologists"? Many meteoroglogists are also members of a professional organization (the name escapes me) and will display that organization's logo next to their name when they're on-screen.

Re:Run your OWN weather station

[gnu-generation-one]

Even if you don't want to run a climate model, try putting XPlanet on your background, and get the updated cloud images every 3 hours.

It's a great way to stay informed about what's happening weather-wise around you, and you'll be able to watch the weather-forecasts with an "I guessed as much", from being constantly aware of the cloud pictures.

Re:Run your OWN weather station

[mr_lithic]

It used to be the case that all British Weather presenters were members of the Met Office

I believe that stopped with the cable and satellite channels. I can't see Ulrika Johnson or Denise Van Outen as a members of the Met Office.

It is quite conforting to see that most of the BBC's weather people still started off in Science Professions, physics,chemistry, and mathematics are represented, before moving to broadcasting.

Re:Run your OWN weather station

[Anonymous Coward]

Woah-woah one second there. Denise Van Outen is actually extremely intelligent. Just because she acts like a bit ditzy sometimes doesn't mean that she's stupid. I know you were just pulling names out the air, but you got that one wrong.

Re:Run your OWN weather station

[Hylander]

> Tying all this historical data back into longer
> range forecasts would be fun. I've found TV
> forecasting to be pretty stale and inaccurate. How
> many of them have real meteorological degrees
> anyway?

Well that would depend where you are. The BBC's weather forecasters are all real meteorologists, and prepare the forecast they deliver themselves.

Hurrah for auntie :)

Re:Run your OWN weather station

[534154414E]

Wow indeed, I routinely worry about the weather at home when traveling beyond Earth's atmosphere. ;)

Tom to Ground Control, come in. Over.

Ground Control here, what's problem, Tom? Over.

I was just looking at my home weather status and my A/C seems broken, again. Could you get a tech over there to check it out? Over.

Sorry, Tom, You've started chsshhhh chshhhshshhh -king up cshshhhhhhhhh...

Re:Run your OWN weather station

[/dev/trash]

For real. I like that one blonde weather bunny. Purrrrrrr

Re:Run your OWN weather station

[Turfoil]

Heather the Weather-Babe! ;) the parent company must have very good benefits, cuz these women pop em out all over the place.

Re:Run your OWN weather station

[mr_lithic]

I did not say that Denise Van Outen was not intelligent, only that she was not a member of the Met Office.

Ulrika is also a very intelligent woman, but I do not remember the Met Office symbol present when she did the Weather reports on television.

My point was that television and radio weather presenters used to be all Met Office members. However, that changed at some point and these two women were the examples of that change.

Re:Run your OWN weather station

[Anonymous Coward]

The BBC weather people are all members of the Met Office but not on the other channels.

Re:Run your OWN weather station

[CAIMLAS]

hrm. where can I get one of those with a military tactical overlay? :) Ala "Command and Conquer"

Re:Run your OWN weather station

[Spunk]

Then may I suggest the Naked News?

Re:Run your OWN weather station

[/dev/trash]

To me she was hotter when she was pregnant, but yeah they seem to be like rabbits at that place. I shoulda been a weather dude.

Re:Run your OWN weather station

[Alien54]

Weather pulse is fairly decent for windows

http://www.tropicdesigns.net/weatherpulse.html

And will also allow you to choose from multiple weather forecast backgrounds.

Amazingly it's not adware not spyware and is freeware

Re:Run your OWN weather station

[Anonymous Coward]

How many of them have real meteorological degrees anyway?

The Environment Canada meteorlogists and forecasters (not the Weather Network TV weather people) typically have a 4 year physics degree, a 1 year meteorology diplomia, and 8 months in-house training when hired.

Re:Run your OWN weather station

[plcurechax]

meteoroglogists are also members of a professional organization (the name escapes me)

American Meteorological Society I believe is the group you're referring to.

Re:Run your OWN weather station

[AlexisMachine]

If you have a degree in Meteorology or Atmospheric Science (basically you took all the hard classes with Calculus) then you're a Meteorologist.

These days, you can get a broadcast Meteorolgy degree from Mississippi State or SUNY Albany, and become an weatherman without all the tough classes.

The logo you're talking about is the
AMS Seal of Approval.

Re:Run your OWN weather station

[Anonymous Coward]

Ever notice how some of the TV weather people are called "weathermen" while others are called "meteorologists"?

Coming soon...

We now turn to our offshore weatherman ... Mohabi, can you please tell us what our weather will be like today?

Yes, Alison. Your weather on thee west coast will be veddy veddy good. And your weather on the east coast will be veddy veddy bad. In the middle, it will be veddy veddy... how do you say good and bad? veddy... veddy ok. Yes, veddy veddy okay. Hot diggity.

Re:Run your OWN weather station

[julesh]

Sorry, Tom, You've started chsshhhh chshhhshshhh -king up cshshhhhhhhhh...

Yeah, I hate it when things start cshing up too.

Re:Run your OWN weather station

[A55M0NKEY]

Who the hell cares if the talking head on the news has a weather degree? I mean the station can probably subscribe to a ready made weather forecast for the weather bunny to read. It seems pointless to get a PhD to point at imaginary pictures on a blue screen for a living. They should do theory or design weather/climate modeling software for a living and leave the pointing at imaginary pictures to someone with a nicer rack.

Re:Run your OWN weather station

[Anonymous Coward]

LOL, that's funny! I'd never really thought about it before.....

Re:Run your OWN weather station

[Anonymous Coward]

LOL, that's right. All who read this are geeks (more specifically nerds) you moron.

Old wives tails

[rf0]

Red sky at night shepards delight. Red sky in the morning shepards warning.

Lot of truth in that saying

Rus

Re:Old wives tails

[Anonymous Coward]

Red sun rises. Blood has been spilled last night.

Re:Old wives tails

[Anonymous Coward]

I thought it was sailor, not shepard.

I guess you're closer to the sheep than the sea.

Re:Old wives tails

[Anonymous Coward]

But what about those of us who are not into sheep?

:-)

Re:Old wives tails

[Professor_Quail]

It has to do with the way fronts and pressure systems move...if there's a red sky at night, it means a high pressure front has moved in (means clear weather); a red sky at morning means just the opposite, an area of low pressure has moved in.

Here's a site with more on weather proverbs:
Weather Proverbs

Re:Old wives tails

[Anonymous Coward]

Didn't know wives had tails!!? I guess we must descend from the monkeys after all, then.

Re:Old wives tails

[Anonymous Coward]

Red sky at night shepards delight. Red sky in the morning shepards warning.

It's "Red sky at night, sailors' delight. Red sky in the morning, sailors take warning."

Why would shepards care if a storm was brewing? They can just go inside.

Re:Old wives tails

[larry bagina]

Why would shepards care if a storm was brewing? They can just go inside.

Maybe today's shephards can, but historically, shepards camped out with their sheep dozens or hundreds of miles from civilization (and women, too...)

I've always heard of it as "sailors", though.

Re:Old wives tails

[Anonymous Coward]

The origin can be traced to the Bible (possibly before, but don't know of any reference):

Matthew 16:3:

He answered and said unto them, "When it is evening, ye say, 'It will be fair
weather: for the sky is red.'
And in the morning, 'It will be foul weather today: for the sky is red and
lowring.'"

Not only can the colour of the sky be affected by pressure fronts as pointed out in other places, but it can also indicate the movement of cold fronts. I suppose the 'sailor version' is more well known in the US because almost the entire population imigrated by sea... but the 'shepherd version' which is more well known in Europe, will pervade agricultural commuities more.

Re:Old wives tails

[sfm]

Red sky at night, sailors delight
Red sky at morning sailors take warning

(And the important corrollary...)

Brown sky all day, your in L.A.

Re:Old wives tails

[Anonymous Coward]

"I thought it was sailor, not shepard."

Nope, definitely shepherd.

Re:Old wives tails

[swordboy]

Red sky at night shepards delight. Red sky in the morning shepards warning.

Lot of truth in that saying

You can actually use that for most anything because the rhyming has nothing to do with the conditions. For example, you could substitute "green" for the color and "sailor" for the type of delight to yield:

Green sky at night, sailors delight. Green sky in the morning, sailors take warning.

As long as it rhymes, people will think that you are a genious... and it is about as accurate as the weather report so who is the wiser?

Re:Old wives tails

[thedogcow]

I bet you believe the Old Farmers Almanac as well?
People also believe there is an invisable man in the sky.
Wow, people are stupid.

Re:Old wives tails

[Anonymous Coward]

Goatse.cx links, disgusting and stinks.

Re:Old wives tails

[mark_space2001]

I sail on the west coast and in San Francisco Bay. This saying comes the east coast and it has to do with the moisture content in the air. It does work for them but doesn't work on the west coast.

I'm not sure what the equivalent saying would be for SF. Probably something pithy about five to seven fog cycles, which is the biggest hazard on the bay.

Re:Old wives tails

[Anonymous Coward]

They weren't camping, they were dating...

Re:Old wives tails

[Pinky3]

I thought it was sailor, not shepard.

And I thought people who herded sheep were called shepherds.

Re:Old wives tails

[xenocide2]

And the famous corrolary, "If the birds are in the sky and upside down, you're drunk and lying on the ground." Courtesy Bill Engvall.

Re:Old wives tails

[altek]

I am lifting this directly from a Meteorology textbook:

Some of the earliest folklore forecasts in Western culture, such as the following, come from ancient mariners:

Red sky at night, sailor's delight
Red sky at morning, sailor take warning.

This saying is fairly accurate. A clear western sky at sunset allows the Sun to shine through the atmosphere, its light reddening due to Rayleigh scattering and then reflecting off clouds in the eastern sky. Clouds to the east usually move away; storms in the middle latitudes generally travel to the east under the influence of jet-stream winds. The reverse is true in the morning, when the red sunlight shines on storm clouds approaching from the west. However, this folklore doesn't work at all in overcast conditions, or at tropical latitudes where weather often moves from east to west.

So it's generally true in the mid-latitudes, but still YMMV.

Re:Old wives tails

[Anonymous Coward]

My gran can tell exactly when its gonna rain. Seriously, she has some disease of the inner-ear that makes her extremely sensitive to pressure. She calls and says she feels sick like its going to rain and sure enough it does within 3 or 4 hours. She is almost completely blind and deaf and doesn't have a TV or radio, so I dont think her super powers are a trick.

Re:Old wives tails

[Yojimbo-San]

"The red sun rises - blood has been spilled this night."

Re:Old wives tails

[Ignominious Cow Herd]

Yeah, and it is Tales, not Tails. Unless of course it is tails and you're getting some....but Old Wives? Blecch!

Re:Old wives tails

[Anonymous Coward]

there are even some old wives with nice tail!

Re:Old wives tails

[Anonymous Coward]

Red sky at night shepherds delight. minced meat and mashed potatoes shepards pie.

Re:Old wives tails

[75th Trombone]

"Shepherd" is a verb here, genius...

Re:Old wives tails

[Anonymous Coward]

Excuse me, asshole.

Re:Old wives tails

[kien]

This is a great submission. I too was a weather geek before (or rather while becoming) a computer geek.

Here's another bit of trivia related to atmospheric physics that can come in handy: Buys Ballots Law.

Basically, in the northern hemisphere, if the wind is at your back low pressure is on your left (on your right for those of you down south). When you combine that bit of trivia with the knowledge that most bad weather is associated with low pressure, it comes in handy when trying to plan a golf game during a FROPA (frontal passage).

--K.

Re:Old wives tails

[Anonymous Coward]

That gibberish is rated a 4?

The "red sky" phenomenon is caused primarly by high straitform clouds reflecting the reddened sunlight at, well you know, sunrise and sunset. It has nothing to do with "high pressure fronts" whatever
the heck those are. Must be a Penn State graduate. :P

I've seen a lot of beautiful red sunrises with good weather afterward and spectacular red sunsets with deterioring weather following after midnight.

Re:Old wives tails

[Anonymous Coward]

...Move to New Zealand and it will come, don't worry.

Re:Old wives tails

[Anonymous Coward]

Red sky at night.... Barns alight!

Re:Old wives tails

[Anonymous Coward]

...Goatse.cx pictures make life better and richer.

I got it...

[hookedup]

Look out the window.

Re:I got it...

[Anonymous Coward]

But i don't run windows.

Re:I got it...

[PrintError]

You have windows? What are those?

I have to walk all the way to the entrance of my cave to see the weather.

It's my monthly exercise.

A great job...

[wrinkledshirt]

It's a great job... a magnificent physics puzzle, solvable with high level math and some acquired skill.

Coupled with the fact that nobody expects weathermen to be right anyway, must be a great living.

Imagine a nuclear physicist saying, "You know, it's funny, but yesterday all indications were that today was going to be a smooth day for our reactor. How about that, eh?"

Re:A great job...

[thorpie]

"Trust me, i'm a weather forecaster" is my standard "you can trust me line". I still use it, but if forecasts get better I may have to change back to "I'm a used car salesman" or "I work for SCO" or the like.

Re:A great job...

[glrotate]

Alternatively tell them your an economist.

Re:A great job...

[Anonymous Coward]

IANAWM, but my understanding is that accurate forecasting is all about the quality of your data, the quality of your models, and how many times and how far out you can run them, accounting for typical local variations.

The guys who report the weather forecast on TV and radio don't. They're basing their forecasts on the basic atmospheric data and doppler radar. Which is not bad in and of itself, but it's only part of the picture. Forecasting like that is by nature limited in its ability to be accurate. Especially as you get more than a few hours out.

There are models and technology capable of pretty amazing forecasting. But it's too expensive for everyday weather. That's what NOAA uses to track and forecast hurricanes--the stuff that can wreak catastrophic damage. But the side effect is that the hydrologists who work with these models in coastal areas and river basins also have access to the most accurate and distant weather predictions. But it's an NOAA policy to limit its information dispersal so as not to provide competition to business. Their mandate is to provide services which protect the U.S. interests and populace.

It's far beyond what the media has time or interest in providing. Besides, the most important part of weather forecasting is to know in advance of potentially dangerous weather, and that message gets out when it exists.

Incidentally, here outside Boston I've just cleared ~26" of snow from my--thankfully short--driveway. More where it drifted, predominantly around the cars, of course.

Re:A great job...

[GuidoDEV]

I've got an AthlonXP 2100+ and can run an 84-hour forecast using the MM5 in 2 1/2 hours. The domain is the continental US (plus some buffering around the CONUS, such as southern canada, parts of the atlantic/pacific, etc.), with a 40km gridpoint spacing and 30 vertical levels.

By contrast, the Eta model run by NCEP currently runs at 12km grid spacing with around 100 vertical levels (I believe), but the key is that the forecast from a 40km model run and a 12km model run usually differ very little, though the 12km run will have a little better resolution and may be a little more useful as a result. If the model runs have a resolution much better than 12km, however, you start running into problems where events like individual thunderstorms are explicitly resolved in the models' physics, as opposed to simply being "parameterized" (i.e., triggered in the model when certain larger-scale, favorable features are present). This sounds all well and good, but unfortunately the models are notoriously bad at explicitly resolving small-scale features like thunderstorms--much work needs to be done in this area.

In short, the average person can run their own weather model on their PC with no problems whatsoever, it no longer requires a supercomputer to do so. Good luck getting very skillful results beyond days 5-7 in your forecast, though.

Re:A great job...

[b0nes]

Coupled with the fact that nobody expects weathermen to be right anyway, must be a great living. Imagine a nuclear physicist saying, "You know, it's funny, but yesterday all indications were that today was going to be a smooth day for our reactor. How about that, eh?"

Well said, but personally, I don't expect weather forecasters to be right, per se. I expect that they will give me the worst case scenario, so that I can be prepared but pleasantly surprised. These days, I am rarely disappointed.

Something is wrong

[Anonymous Coward]

NYC is 41 degrees North, 74 degrees West. That hardly qualifies as "in the East".

Re:Something is wrong

[cduffy]

Ahh, but consider: 74 degrees west is the same as 286 degrees east. Thus, NYC is obviously much further east than it is west. :P

Re:Something is wrong

[gnu-generation-one]

"Ahh, but consider: 74 degrees west is the same as 286 degrees east"

What'll really bug you is whether new york is +40, -73, or +40, +73... It can get quite confusing to use US map data, and to find that New York city is in China

(hint: americans don't like to think of themselves as in the negative half of the world, whereas everyone else likes to have their maps the right way around)

Re:Something is wrong

[Anonymous Coward]

(hint: americans don't like to think of themselves as in the negative half of the world, whereas everyone else likes to have their maps the right way around)

I don't know, the further west you go in the US, the more negative we are....
It is interesting that positive values are on the right of the scale, and the further to the left you go, the more negative you get!

Re:Something is wrong

[Webmoth]

I'll say something is wrong... 41 in The Bronx and 74 on Staten Island? Wow, that's some temperature gradient. Must be a front moving in.

Here in the East

[Leffe]

Here in the East

Hmm... Soviet Russia?

Re:Here in the East

[Anonymous Coward]

in soviet russia.....the weather forcasters forcast YOU!@

Re:Here in the East

[Anonymous Coward]

In Soviet Russia, the weather predicts the forecasters!

Re:Here in the East

[Zaiff Urgulbunger]

I think he means the middle east. Although, I'm a bit suprised by the snow. And saying things like "we're having a heck of a weekend", which is not you're typical middle-east speak.

Global warming has a *lot* to answer for!

Re:Here in the East

[bigbadwlf]

I seriously read that and wondered just where the author was east of.

Hell, I'm in the east and there's no snow flying accompanied by wind.

I suppose we're all supposed to know where this guy lives? That's arrogant.

Re:Here in the East

[Anonymous Coward]

Yes, you should. He is the weather guy for WTNH Channel 8. Knowing that this station is in Connecticut, you should have concluded that he lives reasonably close to work. So, it is safe to assume he lives in Connecticut. Connecticut is on the east coast of the U.S., so that is why he refered to it as "the east".

Red sky...

[Anonymous Coward]

"A red sun rises. Blood has been spilled this night!"

math ?

[Anonymous Coward]

a magnificent physics puzzle, solvable with high level math and some acquired skill.

M2p...

I think weather forecast ain't anything to do with maths... Stop watching your screen trying to calculate what is (nearly) impossible to compute. Simple sky-watching, a few low-level basic instruments (measuring temperature and air pressure, mainly) will surely make better forecasts than the ordinary-TV-guy.
He's wrong too often...

Weather Stations?

[Xenothaulus]

Spend time outside. The more you do that, the more attuned you become to the weather and what it's going to do. Yes, I said outside. It's that place on the other side of the window by your desk.

Re:Weather Stations?

[Anonymous Coward]

It's that place on the other side of the window by your desk.

Don't you mean "on the other side of the bars in your basement?"

Re:Weather Stations?

[adamruck]

thats so true

as a kid I did tons of sailing, and its really not hard to predict the weather in a coupe of hours. With a little more practice its possible to predict the way winds will shift with pretty good results.

Then again I dont recomend anyone put all of there trust in there guess for the weather. I have been stuck on the water in a damn near tornado before(a big black cloud formed over my head and started swirling).

Re:Weather Stations?

[RealProgrammer]

spend time outside

My grandfather taught me to watch the birds. They get nervous when the weather is about to change.

Smell the air, look at the sky, examine the clouds, and feel the wind, the temperature, and the humidity.

I can almost always tell whether it's going to rain or not. In central Illinois, that's quite a trick.

Re:Weather Stations?

[ErixTr]

It's that place on the other side of the window by your desk.

What is that "window" thing you are talking about?

Re:Weather Stations?

[Anonymous Coward]

It's that object between you and the big room with the very high blue or grey ceiling that automatically changes to black at night.

Re:Weather Stations?

[nEoN nOoDlE]

Yes, I said outside. It's that place on the other side of the window by your desk.

can't I examine it from my window and get the same results?

Re:Weather Stations?

[cstangle]

Outside? [shiver]
I have vague recollections from a past life of a big, blue, bright room with poor climate control...

Re:Weather Stations?

[Anonymous Coward]

Window?

That's great for the US

[IANAL(BIAILS)]

But what about for us up here in Canada? Anyone know of any good sites for Canadian weather? I usually start looking at the Weather Network (http://www.theweathernetwork.com) since it usually seems to be fairly accurate (at least in the short term!)
Are there any other really good weather sites for Canadian cities?

Re:That's great for the US

[brarrr]

It's gonna be cold, eh?

Re:That's great for the US

[Anonymous Coward]

Here: if you're in Canada, it's going to be fucking cold all year round! That's it for this year's forecast...

Re:That's great for the US

[Anonymous Coward]

How about environment canada (http://weatheroffice.ec.gc.ca/)?

Re:That's great for the US

[girouette]

The Meteorological Service of Canada has a web page at:
http://weatheroffice.ec.gc.ca/canada_e.html . The going was a little rough there for a while (we don't have the resources of the big media outlets to make it look pretty) but it is getting better all the time. It is also the place where the information is guaranteed to be up to date.

Watch out about the images under "weather charts". They are still the large, old-style monochromatic images. (That will change, eventually, to smaller colour images).

Re:That's great for the US

[Rabidbunnylover]

It's raining mortars...haven't you seen the poll?

Re:That's great for the US

[rcpitt]

Cold? Well, sometimes - but right now we here in Vancouver are warmer than Seattle (150 miles South) and sure as heck warmer than the guys in the American North East.

I was out on the motorcycle yesterday and ride all year round. There have been few months when I havn't ridden at least once and enjoyed it.

The other thing I've noticed recently (lived here all my life) is that the forecasts are getting much better - easily 90% accurate 3 days out and almost as good 5 days out (and no cracks about just forecasting rain and being right 75% of the time eh? ;)

Somebody is doing a good job.

Re:That's great for the US

[mks113]

Yes, but when will you get the Mechanic Settlement (WMX) Radar back on the net? The image says that it was taken down October 6th for 6 weeks maintenance. It still isn't up.

Just finished shovelling the drive here. More to come. Sigh. Looking forward to next year in Africa.

Re:That's great for the US

[Anonymous Coward]

But what about for us up here in Canada? Anyone know of any good sites for Canadian weather? I usually start looking at the Weather Network (http://www.theweathernetwork.com) since it usually seems to be fairly accurate (at least in the short term!) Vancouver is a great place to experience Canadian weather. But Niagara Falls is my favourite. Especially with the freezing rain in Winter.

Re:That's great for the US

[Anonymous Coward]

In Canada the only organisation doing weather prediction is Environment Canada (www.ec.gc.ca). Everyone else, your favourite country station raving about their ACCU-WEATHER and SUPERFORCAST are... just reading the forecasts from Environment canada. Nobody has their own radar, it's all EC's.

Re:That's great for the US

[Anonymous Coward]

WMX will not be coming back. All the services are going to be done out of Halifax, despite the lessons taught by the hurricane. Oh well, your government working for you.

Re:That's great for the US

[schon]

if you're in Canada, it's going to be fucking cold all year round!

Sure, if you consider 35 degrees Celsius "fucking cold" (at which point I have to ask, where the fsck are you from?)

In the winter, it does get cold here (occasional dips to -35c or colder) but summer is quite warm.

Re:That's great for the US

[AndroidCat]

Make it look pretty? Actually I miss the text-only pages. It was easy to have Merlin (a talking Clippy) speak the weather without having to strip out the HTML. If you must nu'n'improve things, how about some XML mutant?

Re:That's great for the US

[nicklott]

Try poletopole.org. We're a bit lacking in forecasts at the moment, but current conditions are much better than most of what's out there (esp the Weather Network).

Re:That's great for the US

[Bob McCown]

Bah, the 4 weather patterns follow the seasons in Canada: Mud, Snow, More Snow, and Construction.

Re:That's great for the US

[plcurechax]

Try poletopole.org

Other than their data for Canada (or any non-US site) may be up to 45-50 minutes late because they used publically accessible data via NOAA.

The most accurate and up to date source of Canadian weather data free for the public is via weatheroffice.ec.gc.ca. Data delays are roughly 5 minutes or less "from the wire."

The Weather Network (in Canada) are poor at not updating their forecasts and not cannot beat the source of their raw data, Meteorological Service of Canada (MSC) Environment Canada.

Re:That's great for the US

[girouette]

I encourage you to use the comment form on the site.
I can vouch for the fact that user comments are read and taken into account. The site's maintainers actually have a sincere concern for accessibility.

Re:That's great for the US

[smnoel]

I actually have a live feed directly from the Environment Canada.

I am working on a personal project to provide live Canadian weather via a new portal website. Free to everyone of course for personal use...

I have not been working on the project much lately because of my job. :-(

In any case, I can attest that the folks at Environment Canada are really nice and when I spoke to them about my project they were very helpful. I have a live feed for xml weather forecast, current observations and also past observations from their website but I still have to figure out how to get the xml to feed on my weather site portal. (I am just a part time web enthusiast)

If your interested in helping me out we could do something really neat and cool for everyone.

email me: gabe at lesnoel.com

Re:That's great for the US

[AndroidCat]

(See XML WX response to elder sibling post.) I'm not really at the stage where I was planning to look at this again. But plans change. I'll sleep on it. (Nothing is worse that getting a really neat key piece of a puzzle -- ahead of schedule!)

Re:That's great for the US

[STFS]

Take a look at this weather site. As I understand their weather forcast is pretty often accurate.

It seems to have data for Europe and S-N-Atlantic but is lacking for other areas.

Their animated charts are cool (animated as gifs so there are no browser issues).

Re:That's great for the US

[smnoel]

Let me know how Morpheus counseled you.

Where's the raw data?

[Quixote]

I work in machine learning, and weather forecasting has always seemed like an interesting problem to explore. However, the lack of accurate raw data (temperature, dewpoints, pressure, humidity, precipitation, etc.) going back 30-40 years is a handicap. Where can one get such raw data, in a machine-readable format?

Also, I have been toying with the idea of writing a script to automatically grade the predictions put out by Wunderground and Weather.com, to see how accurate they are. It would be nice to see if it is really worth it to rely on their 5-day forecast.

Re:Where's the raw data?

[aemain]

NOAA's National Climatic Data Center has a lot of the raw data available, most of it for free (especially if you're coming from a .edu domain). Both US and international data.

Re:Where's the raw data?

[drooling-dog]

A few months ago I wanted to putz around with some hourly temperature data covering a year or so for a couple of cities. Since this data is produced by the National Weather Service using MY tax dollars (OK - yours too), I was sure I'd find treasure troves of it online.

Wrong! What I did find was a couple of companies that wanted quite a bit of money for it. Since I was just playing around anyway, I passed on that. As with all other evils, I'm sure the republicans are to blame for this...

Re:Where's the raw data?

[bastion_xx]

Good question. If other agencies such as NASA and USGS can make a good portion of data available, for free, on the Internet, I wonder why the Weatheer Bue^H^H^H^H^H^H NOAA can't?

Especially for low maintenance things such as raw weather statistics. I can understand if they we're trying to charge for satellite imagery and such.

Re:Where's the raw data?

[catfry]

Also the European organisation for the exploitation of meteorological satellites

Re:Where's the raw data?

[Quixote]

I'm sorry, but detailed (hourly?) data is almost all for pay. Everywhere you look, you'll have to pay to get at the data. Please browse around in that site and see if you can find detailed data for free. I could not (but I could be mistaken, and wouldn't mind being corrected).

Re:Where's the raw data?

[plcurechax]

A few months ago I wanted to putz around with some hourly temperature data covering a year or so for a couple of cities. Since this data is produced by the National Weather Service

Did you try the National Climatic Data Center?

I found the data for $10 (Climate Data Online, NCDC) for a download.

Re:Where's the raw data?

[dpatil]

Because of the larage amount of raw data that is obtained (sats, weather balloons, etc) most of it isn't archived. The post process data can be obtained from the NCEP if you e-mail them. If they charge it is usally only the cost of transferring the data. What might suit your needs better is the NCEP Reanalysis Project. I had downloaded this set a few years ago and it contains data averaged over every four hours on the 2.5x2.5 degree grid and it is free! If you dig around I'm sure it is posted (I met some people a couple of months ago that had just downloaded it). You will have to use a file reading script (free) [like netcdf] to read the data.

Re:Where's the raw data?

[_Pinky_]

Well that can be summed up in a few words...

Government agencies can not compete with public companies. Period. If a private company provides the service, the government can not.

I work for the weather service and anytime we make anything new available for the public, we have to go through this whole process to make sure it shouldn't be provided by private business.

Sure, makes me upset, makes everyone upset... But you have to admit, get some lawyers, some lobbyists, and just take the data that the government service does provide, and then sell it to the public and businesses... Mkae sure the government can't augment or improve what gets sent.. Classic business model...

Re:Where's the raw data?

[drooling-dog]

I work for the weather service and anytime we make anything new available for the public, we have to go through this whole process to make sure it shouldn't be provided by private business.

Ideology aside, the real reason for this is that private companies can make campaign contributions and government agencies obviously can't. Every time another function of government is "privatized", it's another opportunity to effectively collect kickbacks.

In a related story...

[cr@ckwhore]

Meanwhile, weather forecasters around the world were puzzled Sunday as access to weather data over the internet crawled to a halt. A Whitehouse representative denied rumors of a terrorist attack on the weather infrastructure.

The mysterious cause of the delays in weather data are under investigation.

Re:In a related story...

[Anonymous Coward]

It serves them right for not using open source weather!

Re:In a related story...

[Webmoth]

As they say here on Slashdot, if you don't like the weather, just wait 5 minutes and you'll have gnu weather.

If Only it was right!

[mstieg]

Here in Seattle the weather forcasts are wrong more than they are right. They're so bad I quit checking the forecasts years ago.

If forecasters got paid based on accuracy, they'd owe me money!

Re:If Only it was right!

[no reason to be here]

Here in Seattle the weather forcasts are wrong more than they are right.

How the Hell can you screw up a weather forecast for Seattle?

"Tomorrow's weather forecast: 'Rain'"

Re:If Only it was right!

[Laplace]

Try this trick on for size. You live in Seattle, so the weather does follow some predictable patterns. Look to the south-west. Any approaching warm fronts will be coming from that direction. You can get up to two hours of warning of oncoming rain. Swing your gaze to the west/north-west. High cirrus clouds on the horizon predict rain up to 8 hours ahead of time. It's amazing how accurate you can become at predicting the daily weather with just a little practice.

Re:If Only it was right!

[bwalling]

Here in Seattle the weather forcasts are wrong more than they are right.

It's that way everywhere. Meteorology is not a science, it's voodoo!

Re:If Only it was right!

[mstieg]

Uhhhh...if it's that easy why can't the dozen or so media weather forecasters do it right?

I hung out with Rich Marriot of King 5 once and he does all of his own forecasting (apparently most of the TV people do their own work, even for the same station [meaning the morning guy does his own, as does the evening guy]).

But they still can't hit it.

Re:If Only it was right!

[Lispy]

"They're so bad I quit checking the forecasts years ago."

Yup, just as with Computers, last time I checked they were damn slow so I quit using them years ago.

Re:If Only it was right!

[Laplace]

But the forecasters on TV are trying to do something much more difficult. They're looking 24 hours or more into the future, which remains a difficult task which is full of error. Errors in forecasts probably grow exponentially with time, which is why commercial weather prediction (the kind meant to make you "Tune in at 11") sucks as much today as it did ten years ago.

Re:If Only it was right!

[gurustu]

Seattle (and West Coast) accuracy is always going to be lower than you'd like (and lower than the East Coast's, for example) simply as a result of fewer observations.

The rest of the nation gets to see weather data from thousands of weather stations as patterns move from West to East, while Seattle gets its (relatively) skimpy data from satellites and scattered ocean stations.

Re:If Only it was right!

[Anonymous Coward]

If forecasters got paid based on accuracy, they'd owe me money!

See chapter 13 of Jaynes's book on probability theory (pages 5-6 of the PDF document) on an interesting optimal method for paying weather forecasters based on their accuracy.

Re:If Only it was right!

[Anonymous Coward]

Wow! You dictate to a secretary what to post to /. in your name?

Re:If Only it was right!

[Jon Abbott]

It has been my impression that Seattle has fairly predictable weather, at least during the winter months...

Sunday: Rain.
Monday: Periods of rain.
Tuesday: Rain likely.
Wednesday: Breezy and rainy.
Thursday: Rain.
Friday: Chance of rain.
Saturday: Occasional showers.

Lather, rinse and repeat for each week.

:^)

Re:If Only it was right!

[caropepe]

Let me get this straight: forcasting accuracy is less accurate because there is a smaller quantity of current observations? I don't think so... There is plenty of information regarding what is coming. The problem is that they don't know what is going to happen when it all gets here (Seattle). As the weather moves in from the west, it bends around the Olympic mountains (both from the north and the south) and converges over Seattle. What happens next is anyone's guess. This is what makes it a real challenge to predict the weather in the Seattle area.

Re:If Only it was right!

[SB9876]

Last time I checked a few years ago, Seattle weather forcasts were right less than 50% of the time. 'Course being by an extended arm of ocean and between two mountain ranges tends to do that. IMO, the forcasts there need a 'for entertainment purposes only' discalimer in front of them.

Not sure they've gotten more accurate....

[analog_line]

I'm in the Beverly/Salem area and at least the numbers I've been seeing for accumulation are all way too low. They're saying 7-14 inches total for the weekend on NECN for our area, and I personally walked through at least 7 inches of new undrifted snow that has fallen between 2:30 AM and 12:00PM. There's two foot of fall out there if there's an inch, and the snow plows STILL can't keep up with it. 4 foot plus drifts. There was 3 feet of snow on two of the three doors, and the other only a foot and a half.

7-14 inches overnight, I can believe. For the whole storm is utterly ridiculous. Don't know where these people are getting their figures, but someone around here isn't looking out the window, all I have to say.

Re:Not sure they've gotten more accurate....

[Anonymous Coward]

Even stranger, the T claimed that Newburyport trains were running with "5-10 minute delays" yesterday, and they're only up to half an hour now. With this much snow, I don't see how they can run trains at all.

Then again, the roads are so clogged that no one could get to the train station in the first place, they could not be running trains and no one would know ^_^.

Re:Not sure they've gotten more accurate....

[no reason to be here]

Official numbers are taken from wherever the official weather station is located. Here in Dallas (where I'm living), the numbers are taken from the measurements at D/FW Airport (between Irving and Ft. Worth, TX.) which causes some interesting situations. One summer, despite rain falling all over the Metroplex, the drought we had been going through continued unabated, as no rain fell at the Airport.

Re:Not sure they've gotten more accurate....

[Anonymous Coward]

Wind blows snow around. Are you sure you weren't walking in an area where snow just happens to accumulate more?

The Fraud is finally exposed...

[Dr Reducto]

The easiest job in the world?

Weatherman in San Diego, California.

Re:The Fraud is finally exposed...

[Enteebee]

I'm not so sure. Suppose your "75 and Sunny for the next 72 weeks" forecast is interrupted by a "78 and Sunny"? People would call for your resignation I'm sure. Here in Buffalo, you could forecast "Sun and clouds, between 25-75 degrees in the morning, with a 47.3% chance of a rogue snow squall by 3PM. Possibility of thunderstorms this evening, maybe some clearing towards dawn." People would praise your accuracy =)

Re:The Fraud is finally exposed...

[Anonymous Coward]

No no no, even easier: the weatherman in Melbourne, Australia.

"And the weather today, 20 and fine." Every day

Re:The Fraud is finally exposed...

[Shadwell]

You could have at least credited Lewis Black with this one.

"So what's the weather like today John?"

"Uh...nice. Back to you."

Re:The Fraud is finally exposed...

[Josh Booth]

Hardest? Maybe Flagstaff, Arizona. "Well folks its just started to rain... no it's sunny and 78... no its 69 degress, overcast with 15 mph winds..."

There are only 10 types of people

[Anonymous Coward]

those who understand METAR and TAF and those who don't...

e.g.:
(Terminal Airport Forecast of J-F Kennedy Airport)
2002/11/17 09:14
KJFK 170914Z 170913 03021G32KT 6SM -RA BR OVC012
TEMPO 0913 3SM RA BR OVC008
FM1400 02013G20KT 5SM -RA BR OVC012
FM2100 36011KT 5SM -RA BR OVC020
FM0400 34009KT 5SM -RA BR OVC015

Re:There are only 10 types of people

[Anonymous Coward]

TAFs (as forecasts) may be accessed here.
METARs (as reports) there.
The only thing you have to know is the four letter ICAO location of your closest airport.

Go there to find it out, and then... you'll have to decypher the stuff. Have fun !

I know a PHP package that does it quite well.

Re:There are only 10 types of people

[thedogcow]

I do!

Time : 1709Z
Winds: 21 knots from 030 gusts to 32knots
Visibilty: 6 Statute miels
Weather: Rain showers
Clouds: overcast at 1200 feet
And so on.

Re:There are only 10 types of people

[nicklott]

Sorry, have to plug my own site here... :)

I know a website that does it all for you

Re:There are only 10 types of people

[AlphaOne]

BZZT. Try again.

On the 17th, at 09:14 GMT, winds were from 030 at 21 knots, gusting to 32 knots. Visibility was six statute miles with light rain and mist. The sky was overcast at 1200 feet.

Temporarily, for less than two hours, between 0900 to 1300 GMT, visibility will drop to 3 statue miles with moderate rain and mist and the ceiling will drop to 800 feet overcast.

From 14:00 to 21:00 GMT, winds will shift to be from 020 at 13 knots, gusting to 20 knots. Visibility will rise to 5 statute miles with light rain and mist. Sky will be overcast at 1200 feet. ... etc. They're actually easy to read if you do it often enough. I can usually decode METAR faster than I can read an ordinary plain-english forecast.

Re:There are only 10 types of people

[thedogcow]

Close enough for government work*.

*Of type National Weather Service or various NOAA facilities

Aviation wx

[Alioth]

As a GA pilot, I'm always very interested in the weather. One of my favorite sites for weather in my area is westwind.ch which has a lot of good stuff, and of course the good ol' Met Office aviation weather service. When in the United States, I tend to use the NOAA's ADDS service.

Programing for dummies

[KillerCow]

Yes, there are a zillion sites that already have the finished forecast, but this is Slashdot. We don't need no stinkin' forecasters!

Find a problem that has already been solved, and re-solve it.

Re:Programing for dummies

[corbettw]

Find a problem that has already been solved, and re-solve it.

Hey, isn't that Sourceforge's tagline?

Re:Programing for dummies

[AndroidCat]

There's nothing wrong with re-inventing the wheel so long as you can make it rounder.

On this note, but something completely different..

[cshuttle]

Since I was real little, I'd always been interested in the weather and forecasting and all that stuff. Now that toasters and other such standalone devices are becoming so prevalent, I'm looking for the simplest thing that apparently doesn't exist:

How about an 802.11 weather station?

I'm just looking for something that sits outside my house, collects weather data and other such simple stuff, and relays that data back to a server to build a web page with or whatever.

True, there are some devices like this available, but they all require a dedicated machine to log the data, and some really hard work to make them operate properly over a network (why would I possibly want a 1-wire data transmission solution, or even phone-line communication when I've got 802.11 right here?)

Have I simply missed the magic google search that has the toaster I'm looking for?

how about ... Environment Canada?

[Anonymous Coward]

Oh, I don't know... how about Environment Canada? You know, the place the weather network and every other forecasting service in the country gets their data...

weatheroffice.ec.gc.ca

Lorenz Equations

[Stranger4U]

I wonder what relationship (if any) exists between current weather models and the ones created by Lorenz back in the '60s. Those simple equations can produce some very chaotic behavior, and were the influence for the infamous "butterfly effect."

Re:Lorenz Equations

[Anonymous Coward]

Attention crack smoking moderators: Lorenz Attractors, while being chaotic mathematics by nature, are not at all related to weather phenomena. The "butterfly effect" is described as an analogy to the "sensitivity to initial conditions" problem ("A butterfly flaps it's wings in china, and it rains in los angeles").

Re:Lorenz Equations

[thedogcow]

Of course

NWP has a threshold after some time interval and will eventually become worse than climatology but better than persistance.

There is a nonlinearity associated with NWP aka butterfly effect.

Re:Lorenz Equations

[Stranger4U]

Actually, Lorenz's first paper on the subject "Deterministic Nonperiodic Flow" was motivated by computer simulations he ran using a set of three highly coupled, non-linear differential equations that represented a simple weather model. The solutions to those equations will yield the very standard butterfly-wing graph, as well as exhibit sensitive dependence. It was on the basis of this model that Lorenz several years later coined the famous "butterfly effect" term. So, it was initially a weather model, and that's what my post referred to.

Re:Lorenz Equations

[Anonymous Coward]

hehe.. so you knew the answer to your question, when you posed it. As you may also know, the difference between Lorenz model and the mordern ones, is the lack of spatial resolution in Lorentz model :)

Re:Lorenz Equations

[rfovell]

I wonder what relationship (if any) exists between current weather models and the ones created by Lorenz back in the '60s. Those simple equations can produce some very chaotic behavior, and were the influence for the infamous "butterfly effect."

Lorenz' equations were extremely simplified versions of equations employed in weather models. Indeed, unlike weather models, Lorenz' model doesn't attempt to simulate a system with a stupendously large number of degrees of freedom (points or grid cells in space, field variables like three velocity components, temperature, pressure, various forms of water substance, unresolvable mixing, etc.). Instead, it was a simplified representation of "convection rolls", as might be produced in a vessel heated from below. These can be more faithfully simulated with more sophisticated numerical models, tho at far greater expense.

It isn't really the number of degrees of freedom that makes prediction of both global weather and the Lorenz system so difficult, though, it's the nonlinear terms. Though extremely streamlined, the Lorenz system has nonlinear terms.

What we call the Lorenz model started with a two-dimensional fluid (bounded by free surfaces above and below, as I recall) and, by making assumptions about the structure the convection rolls would take, boiled (no pun) the problem down to three simple equations in three unknowns. The variables were called X (proportional to the intensity of the fluid motion), Y (proportional to the horizontal temperature difference) and Z (reflecting the vertical temperature difference that drives the convection).

The deceptively simple equations are
dX/dt = -sX+sY
dY/dt = -XZ+rX=-Y
dZ/dt = XY-bZ
The equations are coupled (changing X affects Y, etc.) but the interesting terms are XZ and XY, the nonlinear terms. Without them, the equations are very dull :-)

Many weather models take a 3D domain and divide it into grid cells and then solve equations numerically for the airflows in and out of the cells and cell-average properties like temperature, pressure, humidity, etc.. The equations yield, for each grid cell, a time rate of change for each variable. The forecast is then made by starting with a present value for each field and extrapolating the estimated time rate of change over a specified time step. That becomes the present state used to recalculate the time rate of change, producing the next forecast in the sequence. The final forecast is the end product of a very long time stepping sequence.

So, essentially, the procedure is a sequence of extrapolation and recalculation based on the extrapolation. That doesn't sound very encouraging, but really that's only because of the nonlinear terms.

Re:Lorenz Equations

[Anonymous Coward]

Roughly speaking, the differential equations are of the same type: linked together in a non-linear fashion.

This is silly.

[Anonymous Coward]

"It's a great job... a magnificent physics puzzle, solvable with high level math and some acquired skill."

I hate to cast a damp towel on this, but personally, I find this is to be silly self-promotional drivel. What Weather forecasters won't tell you is that anything beyond a 3-5 day forecast is just a guess. Their accuracy rates beyond this period go down below 50%; which means that flipping a coin is more accurate. What's more, there have been little changes in improving this accuracy over the past 30-40 years. Most of the improvments have been in the under 5 day forecast. This is despite a great addition in technology (like satellites and computers).

Here's one study which shows this: http://www.nwas.org/ej/rose/verify.htm

There are others. This has been known for decades, but is generally kept quiet.

So the next time you see a Weather report on the news telling how it's going to be 3+ days out, mostly it's just a guess.

You are better off saving your CPU cycles for something more valuable, like Primenet (www.mersenne.org), IMHO.

Re:This is silly.

[azaris]

"It's a great job... a magnificent physics puzzle, solvable with high level math and some acquired skill."

I hate to cast a damp towel on this, but personally, I find this is to be silly self-promotional drivel. What Weather forecasters won't tell you is that anything beyond a 3-5 day forecast is just a guess.

So what? There are a lot of fields in science where most of our knowledge is about making accurate guesses and then seeing how well they fit the reality. It's not just about weather, the same tools can then be used on other complicated dynamic systems.

Their accuracy rates beyond this period go down below 50%; which means that flipping a coin is more accurate.

Really? I'd hardly call predicting the weather a simple case of true-or-false. Otherwise they could simply always give the exact opposite result that the complicated computer simulation gives and arrive at over 50% accuracy.

Though there are some places (like Ireland, I've heard tell) where simply predicting rain every day will be correct 80% of the time.

You are better off saving your CPU cycles for something more valuable, like Primenet (www.mersenne.org), IMHO.

Computer scientists and their everlasting silly infatuation with primes... There are other important research areas, you know.

Re:This is silly.

[thedogcow]

Oh now now,

Don't be upset at this ignorant dullard. You see, you know you are right, I know I am right, so, in lieu of this, next time there is a tornado entering his county, we being the stupid meteorologists who guess at everything, well...

We'll just guess *not* to issue a tornado warning for his location. Lets see if he really understands F=MA then, which of course is what *we* know the atmosphere is based on in its *simplest* form (cough *complicated PDEs* cough)

I'm guessing (Look!) that a piece of steel traveling at 318mph (an F5 tornado) has a lot of force and can easily pierce something.

Re:This is silly.

[Muad'Dave]

Really? I'd hardly call predicting the weather a simple case of true-or-false.

This is what I want out of a weather forecast - will detectable precipitation fall from the sky within a mile of my house in the next 24 hrs? A simple boolean question. I don't care if it's a millimeter or a foot - precip/no precip.

Re:This is silly.

[Anonymous Coward]

Fine. Then be honest and say that it ISN'T solvable.

The claims that are currently being made, that it is solvable, and that they know what's going to happen beyond 3-5 days, puts weather forecasters in the same league as used car-salesmen. Knowingly lying, and generally trying to deceive the public in order to justify their paycheck.

Re:This is silly.

[Anonymous Coward]

A butterfly is flapping its wings in Austrailia. Heavy winds predicted for North America.

Re:This is silly.

[b0nes]

Though there are some places (like Ireland, I've heard tell) where simply predicting rain every day will be correct 80% of the time. There is nothing special about predicting rain, or any other given weather, in a place with strong statistical trends, eg your example, such as predicting rain in Prince Rupert (B.C.), or say snowfall in Phoenix. The whole point about developing this field is being able to predict the unusual and severe weather, weather that might cost lives, livestock, money, danger, whatever. The rest is just gravy, IMHO.

Lookit

[UtilityFog]

One of the best pattern-detection and analysis systems out there is still the human visual cortex -- watch the radar for your area consistently and you'll soon start getting a feeling for what is going to happen next. Wunderground's regional is about the right size.

Quasi-geostrophic/Semi-geostrophic Theory et al

[thedogcow]

Forecasting the weather is all about the quasi-geostrophic theory (or semi-geostrophic theory if you're in graduate school).
QG Theory tells us were there will be differential vorticity advection through a layer or differential temperature advection through a layer (dT/dz increases with height) there will be height falls and omega (vertical advection term) will be negative thus rising motion.

So next time you feel like insulting your local meteorologist and state its a job where they are paid to be wrong, remember if you can find out where cyclonic vorticity advection increasing with height is located and what exactly the laplacian of that will tell you regarding as the impetus for change in the troposphere.

Street-level doppler

[dmoore]

In a lot of US metropolitan areas, there exists so-called "street-level" doppler radar which can show what the weather is doing down to street-level accuracy. I see a lot of TV stations advertise this capability, but honestly, it's pretty useless on TV because it's very unlikely they are going to show me my street during a broadcast. Are there any websites out there that give access to the data from these street-level doppler systems? I'm thinking something like Yahoo maps except with the current weather overlayed on top of all my searches.

Re:Street-level doppler

[vortexf5]

Are there any websites out there that give access to the data from these street-level doppler systems?

Don't bother. There is no radar data available to civilians that has that kind of resolution. They can put all the resolution they want in the map, but that doesn't make the data be that resolution.

At a beamwidth around 1 degree, at just 25 miles from the radar, the half-power beamwidth is already >2000 feet. The beam is a mile across at a range of only about 60 miles from the radar.

Therefore, you don't have to be very far from the radar before the margin of error is much greater than a city block.

Just look at the National Weather Service radars. They are technologically far superior to any of the TV radars.

I live in Missouri

[p51d007]

We only care about the weather for the next
4 hours. Why? Because ESPECIALLY in the winter,
it will change 2 or 3 times a day LOL.
Seriously, I feel sorry for the weather forcasters here (southwest Mo), there have been times that the weather has gone from: sunny 60+ degrees, then cloud up, rain, then thunder & lightning, then at the SAME TIME it is thundering, we get hail, freezing rain, sleet, then change over to snow!
There have been times, that we've had all of those, PLUS a tornado!! The only weather we haven't had here is a hurricane!!!
The old line we use around here, and it's true most of the time (except for summer)....don't like the weather, just wait, it will change in 5 minutes...

Re:I live in Missouri

[ChipMonk]

When the Blizzard of '78 hit, you had, in essence, an inland hurricane. Two low pressure systems merged, producing a single system that was deeper than either of the original two. It then pulled moisture from the south, and cold air from the north. Voila, hurricane over land.

Twain on Weather

[handy_vandal]

"If you don't like the weather in New England, just wait five minutes."

- Mark Twain

Re:Twain on Weather

[glitch!]

"If you don't like the weather in New England, just wait five minutes."

I think you can generalize this to replace the token "New England" with pretty much any place you like. It seems that no matter where you go, people will say that very same thing (inserting their own state or location). And for some reason, they will think that their words are original and insightful.

Re:Twain on Weather

[Anonymous Coward]

Whimps. In Newfoundland, if you don't like the weather out the front door, look out the back.

Re:Twain on Weather

[Anonymous Coward]

We've been waiting for two days and it's still snowing here. Damn that Samuel Clemmons.

Re:Twain on Weather

[b0nes]

Damn, and I just used the last of my mod points two hours ago!

Mod this up!

Don't you know?

[Anonymous Coward]

what a piece of tail is? Man are you ever a geek!

Even better...

[twoslice]

Hang a sock out your window.

If it is warm: it is sunny
If it is wet: it is raining
If it is cold: it is snowing
If it is missing: A tornado blew by....

Re:Even better...

[Webmoth]

This describes my Grandma's cat almost perfectly, except for:

If it is asleep: it is sunny.

Re:Even better...

[ldspartan]

My version of this was always the Weather Rock, a great way to entertain a group of new Boy Scouts for an hour.

If its warm its sunny.
If its wet its raining.
If its white its snowing.
If its moving its windy.
If its missing its stolen.

--
lds

Re:Even better...

[Anonymous Coward]

Of course, you must have intended an apostrophe to be in each of those sentences.

It came back on me :(

[Piranhaa]

Heard about all the snow in eastern US on the news yesterday. I thought it was pretty funny. Low and behold, even stayin up until 5AM today didnt have any snow outside. Now I know not to make fun of others because it'll come back on you. - We were dumped with over a foot of snow ourselves (and still commin) :/ This is definetly a lesson learned ;)

OK, here's a question for mister weatherman...

[cherokee158]

Where do they come up with those percentages? (i.e. 30% chance of snow).

Re:OK, here's a question for mister weatherman...

[Anonymous Coward]

There was a comic strip somewhere that asked the same question. What does 30% chance of rain mean? The comic's progression went something like this:

"It could mean that 30% of the rain will fall on 100% of the people...or it could mean that 100% of the rain will fall on 30% of the people...or there's a 70% chance that the weatherman is 100% wrong."

Re:OK, here's a question for mister weatherman...

[GuidoDEV]

A 30% chance of rain means that the forecaster believes that 30% of the forecast area will receive measurable (>= .01") rainfall.

Re:OK, here's a question for mister weatherman...

[Anonymous Coward]

Good question. Since NWP models are deterministic in nature, for any gridpoint and for a period of time, it will either rain or not, i.e., the models forecast either 0 or 100% probability of precipitation. So where does "30% of rain" come from? The answer is MOS -- Model Output Statistics. By comparing historical observations (e.g. METARs [and yes I can read those and TAFs and TWEBs, too!]) with what the model actually predicted during those times, scientists have formulated regression equations that correct NWP model biases, e.g., model forecast too much light rain beyond 48hrs; max temperatures too high with thin snow cover, etc, etc. In correcting model biases the scientists have come up with regression
equations that look at various model output values and crank out PoP values for thousands of sites around the U.S as often as the model runs per day. Currently there are three flavors of MOS in the U.S. for the forecasters to choose from: Eta, NGM, and GFS.

Hope that answers your question . . .

Re:OK, here's a question for mister weatherman...

[lpangelrob2]

It basically can mean aerial coverage of precipitation... at any point in time during the forecast period, it will be snowing in 30% of the forecast area.

Source? Tom Skilling, of course. :-)

For his better answer, here's a link... http://wgntv.trb.com/news/weather/wgntv-asktom-070 102question.story

Re:OK, here's a question for mister weatherman...

[vortexf5]

Where do they come up with those percentages? (i.e. 30% chance of snow).

IAAMBIDPOOTV (I am a meteorologist, but I don't play one on TV.)

In the National Weather Service, the chance of rain is actually the product of the uncertainty and the expected area coverage. Soooo...

50% uncertainty of 50% coverage == .50 * .50 = .25 or about a 30% chance. Of course, one problem is that most forecasts do not discern between their uncertainty and expected coverage, so exactly what use is it?

Here's mine ;-)

[Lispy]

Weather on a Slashdot head - Slow Day on the Internet

Look out the window

[Anonymous Coward]

It's raining Men.

Re:On this note, but something completely differen

[The Salamander]

I was just looking around myself and didn't really come up with anything.

I'd even settle for a proprietary wireless to a simple basestation with USB/serial. No LCD screen or interface required, or desired.

A simple wired tower/basestation would be fine, too!

Re:On this note, but something completely differen

[RevMike]

How about an 802.11 weather station?

I'm just looking for something that sits outside my house, collects weather data and other such simple stuff, and relays that data back to a server to build a web page with or whatever.

I run a Davis VantagePro Weather station. It relays data from a sensor cluster up on my roof to a console in my computer room via 900MHz radio. Then Davis' WeatherLink software submists it to weatherunderground and to my own website.

What about orange sky at 11:00 AM?

[Skim123]

Here's a picture from my street at 11:00 AM from back in late October. Orangish-brownish, although I think this had more to do with the San Diego wildfires burning 10 miles away moreso than weather fronts. ;-)

Re:What about orange sky at 11:00 AM?

[holt]

I could not justify my existence if I were a turkey farmer. Would I terminate myself? Undoubtably, yes.

I don't understand your sig. What, exactly, is wrong with being a turkey farmer?

Re:What about orange sky at 11:00 AM?

[Skim123]

I could not justify my existence if I were a turkey farmer. Would I terminate myself? Undoubtably, yes.

I don't understand your sig. What, exactly, is wrong with being a turkey farmer?

It's a line from a poem I wrote back a few years ago.

I could not justify my existence if I were a turkey farmer.
Would I terminate myself? Undoubtably, yes.
I would try also to take out a few of those damn turkeys with me.
My bony, middle finger fully extended;
a crude, yet effective, homemade explosive strapped to my nude body;
running wildly around those demonic birds;
cursing Tyson with all my wordly might.
That's how I'd depart this world if I were a turkey farmer.

Re:What about orange sky at 11:00 AM?

[holt]

Heh. I still don't entirely understand. Is this just supposed to be fanciful or what?

Why turkeys? What about chickens? Is it just poultry or other animals like cows and pigs too?

I need to go to sleep. Heh...

Re:What about orange sky at 11:00 AM?

[nmg196]

Red sky at night, Shepherds delight.
11am orange light, Shepherd's alight.

Re:What about orange sky at 11:00 AM?

[Skim123]

In searching for that great tragedy which soiled my youth, I regret to inform that I have yet to find one. I regret not having had an emotionally cataclysmic event as a youth because it would serve quite nicely as a launching point for poetry, polemics, and novellas. I wasn't abused or neglected, no one close passed on; I have yet to commit a grave crime; I have never seen a dead body or an alarming calamidy. So what, then, am I suppose to turn my artistic interests to? Turkey famers? Tacos? My disparagingly low self-esteem? Granted, these provide for immediate amusement but lack any real substance or worth. So I turn my talent to useless abstractions dealing with insignificant topics: Tchaikovsky, nipples, and the Macerena. If I could only com pose an essay of magnificent artistic beauty; if I could but provide a virtual insight into my subconscious psyche. Only then could I justify the immense time I spend recording my thoughts, wants, desires, and pains.

On reporting the recent fires

[Anonymous Coward]

"Uhm we are on scene here and the fires are very hot. Uhm, they are burning everything. Uhm, they are red and orange and uhm there is a lot of smoke and uhm"

So...

[Anonymous Coward]

How about that weather?

Alaska Experimental Forecast Facility

[couch_potato]

For those of you who are more than just superficially interested in the weather, check out the Alaska Experimental Forecast Facility (AEFF) at

http://www.aeff.uaa.alaska.edu

Click where it says 'High-resolution weather forecast products now availabe here' for local discussions and computer-generated ETA/RAMS/GFS plots, plus links galore.

Confused

[Anonymous Coward]

Slashdot makes no sense whatsoever. People are always bringing up beowulf clusters when they don't apply. Now we have a topic where they are used all over the place, and no mention.

Re:Confused

[EmagGeek]

Imagine a beowulf cluster of weather prediction nodes!

Doesn't quite have the same effect as "Imagine a beowulf cluster of these" in a story about a new MicroLinux-drive wristwatch, does it?

You know what they say about...

[Anonymous Coward]

weathermen and economists. They can have long successful careers without ever being right.

Huh?

[drix]

solvable with high level math and some acquired skill.

Solvable? I don't know what high level math you've been smoking, but in my math classes, a problem is solvable when it can, you know, be solved. So kindly tell me what the weather will be in Raleigh, North Carolina on September 16, 2028, and I will stop implying that you're a buffoon. Probably a smarmy one, at that, if you're like all those goddamn weathermen on TV.

Re:Huh?

[thedogcow]

See associated nonlinearity in NWP for such long time intervals such as 2028.

Doesn't matter anway, as you will be dead. The relative humidity of your corpse will be less than 5 percent.

There. Done.
/smarmy_one

Re:Huh?

[Anonymous Coward]

September 16th, 2028 in Raleigh, NC:

High: 76 F
Low: 56 F
Wind: Northeast wind @ 17 mph
Precip: 0.02"
also known as "what is has been on average on that day for the last 50+ years.

If you'd like a more accurate forecast and consider yourself so intelligent, kindly provide me with accurate boundary conditions and initial conditions for a worldwide grid of 1cm (and subsequent conditions on a 1 sec time step) and I'd be happy to plug the values into the equations that have been solved (I have many semesters of notebooks to prove it) and give you an official forecast.

Cheers

Re:Huh?

[Anonymous Coward]

Not "more accurate", how about just accurate. A solved problem has an answer, not a probability distribution. I'm surprised that never cropped up in your many semesters of notebooks.

Re:Huh?

[Anonymous Coward]

I'm sure they cropped up in the notebooks, but unfortunately for you they didn't crop up in the post you replied to. I see single numbers.

Re:Huh?

[Anonymous Coward]

That's funny, the page you linked to gives the (I repeat) average temperature data to date for the month of September in Raleigh. Which would of course ignore such trends as global climate change if you tried to use those values to predict the weather 25 years from now. But that's all beside the point, because the numbers you gave are (I repeat) merely averages. And for the second time, that is no substitute for the answer itself. I don't care what the most probable outcome is, I want to know what the outcome itself will be. Which no one in this world can provide me with. Speaking of the world, do it a favor: burn your notebooks, enroll in remedial math, and stop posting to this forum as if you knew of what you spoke.

Re:Huh?

[Xenolith]

The equations are solvable and they are accurate. It's the garbage in/garbage out that results in the inaccuracies. Can you accurately give the initial conditions...in 3-dimensions for every cubic millimeter of the Earth's atmosphere? Then do you have the computer power to compute to that type of resolution?

Nope. So you do the best that you can do, with the technology at your disposal.

Here a recipe for a cheap weather station.

[smartin]

1. One Wire Weather station from AAG.
   
2. Excellent free software to run it.
   
3. gnuplot to plot the results.
   
4. Post the information to The Weather Underground
   

Re:Here a recipe for a cheap weather station.

[citking]

Weather Underground is an amazing site, full of historical information, severe weather reports, and scientific explanations of the forecast. If you are a regular visitor to the site, you'll notice that the people behind the site are always updating and tweaking things to work better and to provide more features. For $5/year you get the ad-free version (or just grab Firebird if you are stingy) along with unlimited radar access and other goodies.

I've begun using their site over weather.com because the radars on The Weather Channel's site are not updated as often as Weather Underground's, and their site seems to be completely built around advertising, making it hard to find severe weather information and damage reports.

One last thing I like about Weather Underground is its speed. Radars load quickly, my favorites are stored easily, and (at least for subscribers) the layout is impeccable, utilizing a Google-like whitespace rather than cramming sensory overload everywhere.

Kudos to the team at Weather Underground!

Re:Here a recipe for a cheap weather station.

[marnerd]

Just another anecdote about Weather Underground... I started using it when I saw that it was what the folks at NOAA's National Climatic Data Center (NCDC) use. Those folks know their weather. I now pay the $5/year to avoid the ads; this also gets you forecasts and/or severe weather alerts by email.

No affiliation, just a satisfied yadda yadda.

Doppler Radar

[supertbone]

Any one know how to build a dopler radar?

Re:Doppler Radar

[Anonymous Coward]

Yes.

long range models

[Barbarian]

If short-time models can be so different, I wonder how much long-term models can differ, i.e. those that predict a 5 degree warming within 50 years.

Very True

[waldoj]

When hiking the Appalachian Trail, knowing what the weather would be like for at least the next 12 hours or so was as easy and unconscious as knowing how I felt and how I would be feeling in the near future.

Now that I'm off the trail, that skill is all but gone, unfortunately. It just takes a few days out of doors, though, and I start to pick it up again.

-Waldo Jaquith

Re:Very True

[Xenothaulus]

!!!!

Respect. How much of the trail did you walk and where?

Re:On this note, but something completely differen

[/dev/trash]

How come all your wind is coming from the North?

The low tech wind gauge, very reliable.

[Bob Bitchen]

wind sock

Long Term Forecasting

[sjbrown]

Here are some links for the Earth Simulator -- an attempt to model the entirety of the planet's weather systems.

Official Site

Short Blurb from Time Magazine


Descriptive Article (with pictures)

Details Regarding its Supercomputer Status

Re:Long Term Forecasting

[nikmal]

You could also help out with the evaluation of climate models "Climate change, and our response to it, are issues of global importance, affecting food production, water resources, ecosystems, energy demand, insurance costs and much else. There is a broad scientific consensus that the Earth is likely to warm over the coming century, but estimates of how much vary hugely. By taking part in the climateprediction.net experiment you can help to improve scientific forecasts of 21st century climate."

APRS: Also a Mobile Weather Data network

[ivi]

I didn't notice any posts on APRS, the Amateur Radio based position reporting system, which has been used for years to connect & exchange data between mobile, fixed & Internet based sites, including weather data.

The advantage of APRS, even for unlicensed receive-only users, is reception range that by far exceeds that of Wireless Networks (other than, say, 1-way satellite-based Internet connections).

APRS data flows both over VHF/UHF repeaters and from one (RF-based & licensed, ie transmit-capable) APRS station to another.

An APRS shareware (from the UK) that
handles weather data - as well as messages
& position data - is here:

http://www.UI-View.com

There is an excellent introductory site & White Paper on APRS here:

http://vk6.aprs.net.au

You can grab the white paper from here:

http://vk6.aprs.net.au/ukaprswp.pdf

The APRS creator's intro, et al. is here:

http://web.usna.navy.mil/~bruninga/aprs.html

Now that an Amateur Radio license is easier
than ever to get, we should all have one (&
some RF-based voice comms going as we surf,
ie the way that doesn't eat into our 'net
bandwidth, ie via Ham Radio...

with an APRS-connected weather station on
the side, and - when we're mobile (on land,
in the air or on sea - a GPS connected,
so we can be tracked/contacted & even found
in the unlikely even that we get lost. ;-)

Oh, and the speech-enabled Linux-based
GPS-driven, "moving-map" program from Austria - GpsDrive - will help preclude our getting lost
in the first place. (AFAIK, it's not APRS-
enabled... yet, but it lets [WiFi-connected]
near neighbors see each other's positions,
I understand).

Where's the raw data?-Visa or American Express?

[Anonymous Coward]

Yes this is one of the problems. I've mentioned a long time ago that I was doing a sort of desktop weather. However a couple problems. One is the raw data. Second there's all the different formats historical and new, with varying degrees of coverage and accuracy. A person shouldn't have to run a supercomputer in order to get the weather.

Re:MOD PARENT DOWN

[Anonymous Coward]

Thanks for the informative link. All it says is Google. There is a box with a couple of buttons and some links. I clicked a couple of the links, but there was nothing about the saying.

Question about education?

[Andreas(R)]

What kind of education is required to get a job developing and analyzing the forcasts? Would a CS master degree suffice?

Re:Question about education?

[plcurechax]

What kind of education is required to get a job developing and analyzing the forcasts? Would a CS master degree suffice?

How to feel about CFD? Enjoy PDEs?

Typically you need a 4 year (applied) physics degree and a 1 year diploma of meteorology or a degree in meteorology.

Or Ask these guys - met career

Re:Question about education?

[Dr.RealGood]

Wrong, or at least not completely right. Let me clarify... To 'develop and analyze forecasts' like the guys you see on TV, all you need is a degree in Broadcast Meteorology. Forecasting today consists primarily of learning how to handicap the various models, and anyone can learn to do this, with no real physics required. On the other hand, if you want to actually understand how the models work, and maybe develop your own models, then yes indeed you'll need to have an applied physics background and very strong math skills. But the fact is, there are actually very few meteorological positions available that require this kind of education - and just about all of them are with NWS/NOAA. Broadcast meteorology is where all the jobs are, and that's a much easier curriculum.

Re:Question about education?

[plcurechax]

To 'develop and analyze forecasts' like the guys you see on TV, all you need is a degree in Broadcast Meteorology.

Let's just say I don't own a TV, so I didn't even consider the possibly of wanting to be a "TV weather bunny".

To be an "original source" meteorologist (work done at any national weather buro e.g. UK Met Office, MWS/NOAA, MSC/EC, basically any WMO member) you need plenty of education.

To point out Detroit on a map, and read from a teleprompter you need a degree in Broadcast Met.

If I was TV, I'd have to wear pants. :-p

Re:Question about education?

[Dr.RealGood]

Heheh.... Agreed.

For the record, I don't own a TV either.

Re:math ? And forecast accuracy...

[BlueArcus]

Here in the UK, the meteorological office has spent millions on computing power over the past 20 years, but progressively less on actually getting raw input data. As a consequence, the accuracy of the forecasts doesn't seem to have improved that much. GIGO.

In the summer, you get better accuracy in the UK by assuming that tomorrow's weather = today's weather.

Hello from Vegas

[ajs]

Well, this weather in N.E. is having fun with me ;-) I'm "stranded" in sunny Las Vegas for two more days... sigh. I guess I'll have to go find some more desert to explore.... If you come to this area, I recommend Lake Mead. This is the lake created by the Hoover Dam, and is currently at drought levels, but still cool to explore. The area is filled with amazingly cool rocks and some stunning scenery.

Re:The Fraud is finally exposed... In Philly

[EmagGeek]

First, the teaser commercial during the simpsons "RUN FOR THE HILLS, THE SKY IS FALLING!!!! In the form of snow, tonight at 11"

Then, when the news begins, in the most emphatic voice "Heavy snow is falling as we speak all over the Philadelphia area. Some areas * could see 12 inches of snow before it's all over" Of course, neglecting to put the "near Buffalo" where the * is, and not bothering to tell you that they're really expecting 12 inches over the next 3 days.

Always making a big event out of nothing... case and point this weekend...

If you understand this equation

[thedogcow]

... then you too, can predict the weather....

It is the omega equation which tells us where clouds form via rising motion.
here

Mod parent up

[r84x]

I know it is a plug for his own site, but it is worth checking out, very nice, straightforward interface and display, timely data, and very nice graphics/charts/tables. I would recommend it.

Finally!

[MousePotato]

I know this is slightly off topic so mod it as such if you must. It is really nice to this kind of article posted on /. This was the first one in a long time that I actually bookmarked. Great replies and a nice bunch of info in the related links. All in all this is the kind of stuff that I love to see on /. Thanks :)

btw. props to ctwxman for the nice submission!

Re:Finally!

[ctwxman]

Thanks. That was very kind of you to write. All the best, Geoff Fox

Re:Finally!

[MousePotato]

You are quite welcome! I wouldn't have written it if I didn't mean it and I sincerely hope the /. staff keeps up with accepting your submissions. They are the kind that got my attention back when this all started.

Peace

Re:On this note, but something completely differen

[cshuttle]

You know...I'd almost be interested in pursuing this if it could be proven there was a market for it...

I want to control the weather

[IDreamInCode]

Basically take the Earth Simulator computer, that predicts weather patterns across the entire world, and modify it to add points where we can add heat, or remove small amounts of heat to create wind. For instance, if you heat up a cold valley, then wind will be produced by the difference in temperature. If you take colder areas from nearby, you can push the cold air into a hotter area, and vice versa, by creating pockets. I am not a weather expert, but if you simulated the effects on the globe over periods of time, you could easily create weather patterns to remove droughts. Ok, one of the big applications would be for the most recent fires we had... We could have moved the cold front over quicker, or created an on shore flow by heating up the ocean by some space mangnifying glass that heats up specific places of the ocean. I really think this idea could work. Pros: Cool down Mountain resorts so I can go snowboarding more often. Even sell weather patterns for certain places like skii resorts, farmers, etc. Remove famine in 3rd world countries by providing a consistant environment to farm in. Make Southern California an even better place to live in! Cons: If an George Bush gets a hold of this, he'll use it as a weapon of mass destruction... heating up countries he doesnt like, tornados, mass flooding, etc. What I need to do this: 1. Super Computer... estimating 50-100 tFlops Maybe a SETI like project with people running it on their home computers. (fastest computer now is a 30 TFlop earth simulator) 2. Objects in space to heat up certain parts of the earth OR objects on top of hills (mirrors of some sort) to heat up valleys small amounts, few degrees in key points. Simulate this for a couple weeks, and see what happens.

Re:I want to control the weather

[HalfFlat]

This idea was also used by Greg Egan in the backdrop of his story "Permutation City", published in 1994. (The first half of the book I really highly recommend. Feel free to stop reading after that though ...)

In this setting (IIRC), most computer time was up for sale via some bidding system. If you had small problems, sure you could run them locally, but for bigger or more intensive tasks, you'd need to buy time. Computer simulations of actual people, running at about 15% real time, constitute some of these intensive tasks. These simulated people become worried when a project to control the weather, along the lines described above, is initiated and drives up the cost of computing time on the global network.

That's not the main thrust of the novel though - just part of the scenery!

Weather or not

[anazazi]

It's called the weather because you wonder weather it will be or cold or weather it will be sunny or cloudy or weather it will be windy or calm or weather it will be wet or dry. It's just the weather man.

Local Variability

[handy_vandal]

I think you can generalize this to replace the token "New England" with pretty much any place you like. It seems that no matter where you go, people will say that very same thing (inserting their own state or location).

Sometimes true, but not always. Some places have highly volatile weather (e.g. New England). Other places have relatively stable weather (e.g. Antarctica). Degree of variability varies from place to place.

Heather Tesch?

[Vagary]

Would that be Heather Tesch you're talking about?

Re:Heather Tesch?

[holt]

That site is entirely too creepy for my liking. I am amazed that people obsess over weather personalities.

Re:Heather Tesch?

[/dev/trash]

No.

I think this is the one I was thinking about:

http://www.weather.com/aboutus/television/ocms/a be rnathy.html

it's been so long since I've watched the Weatehr Channel though.

Re:Heather Tesch?

[Vagary]

Thankfully they have a site for her, too.

Re:On this note, but something completely differen

[RevMike]

How come all your wind is coming from the North?

Well, there is a low pressure system to my NE. Lows rotate counter clockwise (in the Northern hemisphere. Therefore, my wind would be coming from a generally NW direction. In addition, there is a high pressure system to my W. Highs rotat clockwise. That is moving the wind point a little more to the N.

If you go to the weatherunderground sight and look at the last several days, you'll see the wind coming from the West on the afternoon of December 4th. Over the next several days, you'll see the wind shift to the NE as the Nor'Easter hits, then swing N as the Nor'easter moves NE of me.

Dude, But She's Hot!

[Vagary]

Yeah, it's pretty nuts. My favourite part is how the guy is collecting donations to buy him a satellite dish -- at least he'll be working for it!

Weather in Australia

[Foddrick]

For those of us in Australia, the Bureau Of Meteorology have an excellent site, with radar, rainfall, river conditions, forecasts and whole lot of useful weather information.

Observe the skies, use your intuition...

[vudufixit]

And most likely come close to the accuracy of the most sophisticated forecasters, amateur and professional alike.

Re:math ? And forecast accuracy...

[Anonymous Coward]

Hmm. Objectively, the skill in deterministic forecasts have leveled off in the past 5 years, so you may be right. I doubt, though, its GIGO. Observational data has EXPLODED in quantity and diversity. Most of the weather data comes from aircraft, profilers and satellites, not balloons, which I think you are referring to. Getting all of that data into the models without introducing unphysical effects is a real challenge. In fact, the Europeans, ECMWF, make the best weather forecasts in the entire world, (both Northern and Southern Hemispheres) largely due to the ability to more fully assimulate these weather data into its NWP model.

Close, but no cigar

[Jerry]

As Dr Lorenz demonstrated in 1963, long range weather forecasting to any degree of accuracy is doomed to failure, even using several different mathematical models. Even accurate predictions no farther out than 5 days are limited to wind directions, barometric pressures, and the high and low temperatures. Precipitation, like thunderstorms, is 'predicted' in terms of percent probability that your area will get rained on, but even 0% or 100% predictions have often failed. Five years ago, on Oct 14th, none of the 14 inches of heavy wet snow we received was predicted. It downed over 50,000 trees in the city. Our award winning meteorologist spends about half of each broadcast, following a weather event, apologizing for mis-forecasting the previous day's weather. As Dr. Lorenz pointed out, the various runs of the model 'look similar' but that's not the same as a prediction, nor proof that the weather will even obey the model, regardless of what the model says.

Weather prediction is a standing joke. You are use to it. I am used to it. That's about best that can be done, despite all the high powered computers, mathematical models and and their theories. That's the nature of Chaos. Even when a thunderstorm is raging in the next county and heading in your direction there is no model that will predict if and when it will arrive. The 'meteorologists' at most TV stations use composite radar to 'predict' where storms are heading and when they will get there, and they make their predictions only minutes before hand, not hours or days, weeks or months ahead. I find that I can do exactly the same for the Lincoln area, with exactly the same accuracy, using the Omaha composite radar at www.crh.noaa.gov/radar/loop/DS.p37cr/si.koax.shtml

The best predictor for bad weather on the NOAA website I gave is the one-hour rain loop. But even when it shows a steadily advancing area of wetness, the "Great Wall of Lincoln" has unpredictable effects in diverting or suppressing rainfall. Ditto for snow and tornadoes.

The really arrogant folks are those who use models to predict global weather 50 years from now, even when they limit their 'predictions' to general high temperature 'averages' for regions like North America or Africa. Such dire 'Global Warming' predictions are fueled not by valid math models, because none exist, but by their political agenda. Those kinds of 'predictions' can only be classed as flagrant propaganda, and people willing to fabricate 'scientific' evidence for their political agendas scare me, just as much as folks who pass laws destroying my Constitutional Rights, while claiming to protect those freedoms from the actions of terrorists. They are from the same mold.

Here is a nice java applet demonstrating the Lorenz Attractor.
http://www.exploratorium.edu/complexit y/java/loren z.html

Re:Close, but no cigar

[TheViewFromTheGround]

The really arrogant folks are those who use models to predict global weather 50 years from now, even when they limit their 'predictions' to general high temperature 'averages' for regions like North America or Africa. Such dire 'Global Warming' predictions are fueled not by valid math models, because none exist, but by their political agenda.

Out of pure curiosity (I don't have a dog in the global warming fight), what makes it impossible to find long-term trends in a chaotic system? For example, in my undergrad dynamics course, I numerically simulated a chaotic system of two pendulums whose bobs were linked by a spring and which could be driven, damped, or run fricitionless. In the low damping case particularly, you could predict the outlines of what would happen very well by idealizing some of the trickiness out of the system, but the local behavior was not amenable to such analysis. The system would do all sorts of crazy stuff in short time intervals (1/10th of second or so) but we could still quite accurately predict the stopping time, and the envelope of the motion. You could even plot the more-idealized trajectory and the less idealized trajectory in phase space, and see how the less-idealized trajectory deviated in locally significant but globally insignifcant ways around the more-idealized trajectory.

It is possible but not necessary for chaotic systems to exhibit locally unpredictable behavior (which is unpredictable in principle) and still find solutions for more idealized models that are accurate for long-term behavior. Given that, I'd be curious what literature and theory backs up your assertion that the long-term mathematical models predicting global warming are corrupt. I'm perfectly willing to assent to the claim that the "science" employed here is self-serving, propagandistic, and intentionally ignores its own fatal flaws (intelligent design comes to mind as an example of this, another politically charged area of science), but the chaotic behavior of the weather system at a temporally and spatially local level (as has been demonstrated all over the place) in principle does not preclude the possibility of long term prediction of a trend such as global warming. To argue that it does, you must actually show what models are employed by the global warming partisans, what theories preclude the efficacy of their models, and on what empirical basis.

Re:Close, but no cigar

[rfovell]

Even when a thunderstorm is raging in the next county and heading in your direction there is no model that will predict if and when it will arrive.

Actually, that's not true. The sub-regional scale models tend to be pretty good with thunderstorms and their movements, especially organized thunderstorm complexes. Larger scale models do suffer because they're not actually resolving the storms; they're trying to capture the effects of such storms on the resolved scale atmosphere. Increasingly, however, higher resolution models are being used over relatively short terms (less than 48 hours) where they are revealing some skill.

What is much more difficult is convective initiation -- predicting when and where a storm will occur. Even in this there are frequent successes. A few weeks ago, the Los Angeles area saw a freak hailstorm that just sat over south-central LA and dumped over 5" of rain in a raingage located in Lynwood. My own forecast for this day, made using a 6 km resolution model and available hours in advance, captured this storm beautifully. The problem is... believing it when it happens :-)

The really arrogant folks are those who use models to predict global weather 50 years from now, even when they limit their 'predictions' to general high temperature 'averages' for regions like North America or Africa.

You need to learn the distinction between weather and climate models. Think of the Lorenz equations, in which the solution hops around capriciously from one 'arm' of the Lorenz attractor 'butterfly' to another. Actually, what's happening is the modeled circulation is reversing between clockwise and counterclockwise in these hops. However, you can think of the two arms as 'rainy' vs. 'sunny' if you wish.

Any point on the trajectory at any instant of time is the 'weather', and after a while you're bound to be wrong. But the whole 'butterfly' itself is the climate. The climate model is asking: is the 'butterfly' as a whole changing. I'm not saying that climate models are perfect -- they surely aren't -- but it's possible to get the climate right and the weather wrong.

Re:Close, but no cigar

[ctwxman]

You're right that our accuracy goes down as we go farther into the future, but even having a small amount of additional insight into wind directions, barometric pressures, and the high and low temperatures is incredibly valuable. People live the weather in realtime. The fact that it was nice yesterday makes little or no difference if it's rotten today. But, some businesses and industries greatly benefit from knowing how and when to order and plan based on the coming weather. I actually present an 8 day forecast. I have gone on the air to explain what it does and doesn't do (and it doesn't do a lot). It has been fairly successful in showing temperature trends and less successful at everything else. But, knowing a cold snap will last... or not... has great value.

Hmmm...?

[jellisky]

Each is run using somewhat different equations, making them often come up with different, quite contrary solutions.

Emphasis on "somewhat," please. The dry dynamical equations are well represented and can be written out completely. It's the moisture that's slightly different. Granted, there are different discrete approximations to derivatives and such in some of the models for the equations. But the equations are all fundamentally the same.

It's a great job... a magnificent physics puzzle, solvable with high level math and some acquired skill.

NO!!!
Even the dry dynamics are not solvable, by any mathematics! It's a system of nonlinear equations that is almost fundamentally unsolvable. That's why you still have a job... and why I'm going to have one for ages, too. You can solve simplifications of the equations with some, actually, low-level calculus and differential equations, but the full equations... they're unsolvable. Purely unsolvable.

As for the whole running a model on your own computer, don't expect too much. Unless you run the models at low resolution, the model will take longer to run for a forecast than the forecast is for. In other words, run it at too fine a resolution, and you'll be waiting 12 hours for your 6 hour forecast.
It's neat to do, though. For my graduate work here (in Atmospheric Science), I'm running the RAMS model (similar to the MM5, with its own advantages and disadvantages). It's fun to see the results.

-Jellisky

Re:Weather from around the world

[plcurechax]

The best non-commerical meta-site is the WMO - World Meteorology Organaization's World Weather site.

XML WX

[AndroidCat]

It wasn't exactly a critical application. In fact, it pushed me to work on generalized routines for extracting information from web pages.

The app I'm working on now will eventually have a use for weather info (it makes a really neat demo) but that's still a bit in the future. Hmm, a standard international XML format for weather information would be pretty useful for any app that needs weather info. Not just fancy apps to predict commute time, but farming apps and such with all sorts of trigger alarms.

I've jotted this down in my notes to look at again later.

Re:XML WX

[girouette]

There have been efforts toward using XML in meteorological codes, but so far they have been somewhat scattered and isolated. The US Navy gave it a fairly extensive shot at http://zowie.metnet.navy.mil/~spawar/JMV-TNG/XML/O MF.html

The World Meteorological Organization is ultimately the standards body for international meteorological codes; you may want to have a look at sections 4.2 through 4.6 of this document to get a feel for the way XML is perceived by the WMO (not negatively, but as a complement to already well-established codes):
http://www.wmo.ch/web/www/WDM/reports/FWI S-2001.ht ml

That may be too much information if you only intend to build a quick demo... but the overall background may still interest you.

I can see it now

[lone_marauder]

There are programs available to allow you to run your own model, specifying the domain, grid spacing, time interval, etc.

I have to admit, that is WAY cooler than creating a tornado in SimCity. The only way these tools could possibly come to good use among the slashdot crowd is in the area of theoretical knowledge relating to city-destroying superstorms.

Another Amateur Weather Forecaster

[mccrew]

Since 1996, I have had a Peet Bros. Ultimeter 500 weather station hooked up to a serial port of a Linux box, faithfully recording wind and temperature readings from the top of my house.

Check it out at http://www.mccrew.com/apps/Latest.jsp. There is downloadable Linux software, as well as an online Java client that gives a realtime view of the wind speed, direction, and outdoor temperature.

-Steve

MOD PARENT DOWN -- CANADIAN

[Anonymous Coward]

we don't need no stinkin canuks!

that's "tales"...

[Anonymous Coward]

Also "shepherds", but in that case the misspelling doesn't change the meaning....

However...

[Dr.RealGood]

I guess my point was that these days even state-of-the-art forecasts are prepared primarily by looking at the models first. Knowing the usefulness and deficiencies of the various models and applying that knowledge based on past experience is a large part, maybe the main part, of what real forecasters actually do. Even the NWS guys work this way - look at any NWS forecast discussion and you'll see language like: "latest ETA shows... therefor I am calling for..." etc. This is not exactly the stuff of higher mathematics. The models are tools, and like any other tool they work best when the user has a good idea of the principles that make them work, but you don't need a math degree to prepare a good weather forecast. Working with the models, comparing their predictions with actual current conditions, using all the data available to build up a 3-dimensional picture of the atmosphere in the mind, this is how forecasting gets done. To advance the science of meteorology you will need that physics degree and more, but the original question was about forecasting. With the tools and data available on the internet today, anyone who knows the basics can put together a pretty decent forecast, without solving a single equation. I believe that was one of the main points of this thread.

I am not saying that serious meteorology doesn't require a strong background in physics - I am, however, suggesting that your average day-to-day forecasting doesn't necessarily require any serious meteorology!

Details

[waldoj]

Nearly all of it, in 1996. (I broke my feet, and so I'm missing MA, CT and VT.) I actually carried a laptop and blogged it (although we didn't have that word then).

-Waldo Jaquith

Re:Details

[Xenothaulus]

Kick ass. I recently read A Walk in the Woods by Somebody, which was about hiking the trail, and it made me want to do it. Now I've talked to someone who actually has.

Nah....

[Ratface]

It's "Red sky at night, Reagans delight.
Red sky in the morning, four minute warning!"

(Though one might want to account for modern times by swapping out Bush for Reagan of course ;-)

Not in the SF Bay Area in summer

[billstewart]

Twain's line about how the coldest winter he'd ever spent was a summer in San Francisco applies here, but for most of the area, there are a solid six months that the weather forecast doesn't change, and if you don't like the weather, drive 10 miles. It'll be 50s-60s and foggy by the coast, clearing by late morning, ~70 on the Bay side of the city, ~80 in Berkeley, 80-90 in Silicon Valley, ~90 in Walnut Creek,Concord, and Livermore, and 90-100 in the Central Valley.

"Weather reports" adjust this by at most 5-10 degrees, and adjust the fog times by a few hours, and maybe a dozen days in the season San Francisco will warm up to 80 or 90 because the wind did something weird. Eventually daylight savings time ends and it thinks about maybe raining, but it doesn't really do much of it until January and February, which are what passes for winter out here. If it's an El Nino year, the rain will last a bit longer in the spring.

Fewer Observations?

[billstewart]

That's because it's raining too hard to see out....

My experience with Seattle weather has been better than its reputation - maybe 10% of my trips there have gotten rain, though I've also been there when there was lots of snow around, which was weird. But the stereotype is more like Scotland and Ireland -

• If you can see across the bay, it'll be raining by tomorrow.
• If you can't see across the bay, it's because it's already raining...

You Forgot

[SnowZero]

...
5. Profit!

(in the copyright law financial gain sense of course, where getting information back from others is seen as a profit).

Where's the raw data?-OpenDX

[Anonymous Coward]

OpenDX will read that, among other things.

METAR files

[g.a.g]

I believe this is the right place to throw in a plug to PHPWeather. It's a parser for METAR files, the ones typically sent out from airports. This way, you can have your own page display the actual weather at the nearest airport.

Have a look at Ventus Vigor, where it is used (along with other great news from the wind power business). It's amazing how many countries they have weather data from...

In need of a wheater dataset (urgent :/)

[le_jfs]

Does someone have a good link to a weather dataset?
I'm currently working on a little weather prediction projet, testing whether Hidden Markov Models are useful to determine weather changes. But I need data!
What I need is temp, press, winds and a global weather indication as 'clear', 'rainy' or whatever.

Any language in the set {english, french, german, italian, dutch, spanish} is welcome :)
(now I think of it, others may apply too.)

Thank you all...

astronomically based forcasting

[cardshark2001]

There is this huge disconnect with meteorologists regarding the heavens. Astronomy is not used as a factor in the calculation. As far as I know, even the sun and moon are not used as factors.

This is quite ridiculous, as one can prove that weather is affected by the sun and the moon quite trivially. Scientists know that the sun and moon affect our weather.

So why, when it comes to weather prediction, do they pretend that the earth is in some king of empty box? Perhaps because to use the sun and the moon (and possibly the other planets as well) as a factor in their meteorological model would be tantamount to astrology, and to scientists, that's the "A"-word.

You mark my words, some day scientists will use celestial data in their weather reports. They won't call it astrology, they'll call it "astronomically correlated meteorological rhythms", or something.

Just like "cataclysmic evolution". Well, the scientists were just really angry about that one. Everyone thought Velikovsky was a complete nut. He was, in some ways, but he was also right about some stuff, and cataclysmic evolution was one of the things he was right about. Now that this idea is beginning to gain acceptance, it is called "Punctuated Equilibrium", and that is the official scientific name of it, and if you ask scientists, they will still insist that Velikovsky was a nut who never talked to Einstein.

Look into it with an open scientific mind, and you'll see I'm right.

Mod Parent +Funny

[handy_vandal]

Whimps. In Newfoundland, if you don't like the weather out the front door, look out the back.

Made me laugh!

-kgj

US National Digital Forecast Database

[pease1]

Some might want to explore the US National Weather Service's newest toy, the NDFD. Forecasts every three hours for 5x5km grids (not the normal counties) for the lower 48 out seven days.

Use this software to download the compressed binary data and save it different formats or create graphics
Beware, though... the datasets are pretty large and normally updated every hour.