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

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.