Patricia, Strongest Hurricane Ever Seen In Eastern Pacific, Strikes In Mexico

CNN reports that Hurricane Patricia has made landfall in Mexico; Patricia is notable for having the third-lowest barometer reading ever recorded, and as "the strongest hurricane ever observed in the eastern Pacific or Atlantic oceans." Slate points out that at one point, "satellite estimates of Patricia’s intensity broke the Dvorak scale, peaking at 8.3 on the 8.0 scale. ... In fact, Patricia is now very close to the theoretical maximum strength for a tropical cyclone on planet Earth." The Weather Channel is tracking the storm's path, and predicts "catastrophic damage ... along a narrow path as the eye slices into the interior of southwest Mexico Friday night." Here's a map from the National Weather Service showing Patricia's track as well as projected path.

Comments

Eye collapsed well before reaching shore

[JoeyRox]

As often happens with Pacific storms since ocean conditions for maintaining strength are rarely favorable near coastal areas in that part of the world. Winds were down over 50mph by the time it made landfall.

Re:Eye collapsed well before reaching shore

[Anonymous Coward]

I'm not sure the ocean is to blame for the weakening. Patricia had a very compact inner core and a tiny eye. Strong hurricanes generally undergo eyewall replacement cycles, in which the inner eyewall contracts in and an outer eyewall takes over as the main eyewall. The NHC advisories emphasized the very compact inner core in the 11 AM EDT advisory. The 5 PM EDT advisory mentioned an outer wind maximum, which would be the outer eyewall. It sounds like Patricia was undergoing and eyewall replacement cycle as it made landfall in Mexico. Category 5 hurricanes rarely maintain their maximum intensity for very long. Eyewall replacement cycles typically result in the storm weakening while that takes place. Normally, cool waters associated with the California current (the cool northerly branch of the north Pacific gyre) do result in cool waters in the eastern Pacific, but I don't think that's the primary reason for Patricia weakening. I think an eyewall replacement cycle is primarily responsible for the weakening.

Re:Eye collapsed well before reaching shore

[quax]

Anon comment nailed it, from wunderground:

"Late-afternoon data from a NOAA hurricane hunter aircraft in Patricia indicates that the hurricane is forming concentric eyewalls, presaging an eyewall replacement cycle, where the inner eyewall collapses and is replaced by an outer eyewall that forms out of a spiral band. This process typically weakens the peak winds of the hurricane by up to 20 mph, but spreads out the highest winds of the storm over a larger area. This process typically reduces the wind damage from a storm, but makes a larger storm surge, leading to more storm surge damage."

Re:Eye collapsed well before reaching shore

[Anonymous Coward]

NHC did say that the 190 mph estimate in the last full advisory prior to landfall might be a "generous" estimate. The special advisory indicating that Patricia had made landfall estimated the winds at 165 mph at that time. However, the most recent advisory included an interesting comment:

An unconfirmed sustained wind report of 185 mph and a gust to 211 mph was received from a NOAA/NWS Hydrometeorological Automated Data System (HADS) elevated station (295 ft) at Chamela-Cuixmala, Mexico near the time of landfall. This observation should be considered unofficial until it has been quality controlled.

Re:How did it fit on a scale it broke?

[Anonymous Coward]

Dvorak is derived from sustained wind speed and pressure. The wind speeds are so high, and the pressures so low on this storm that they exceed the theoretical maximum (8.0) listed for Dvorak.

I assume they calculated it at 8.3 by extrapolating from the existing scale.

"Third-lowest barometer reading ever recorded"

[Solandri]

That's not quite so exclusive as it sounds. There are a lot of storms with the same barometer reading

870mm - Typhoon Tip (1979)
875mm - Typhoon June (1975)
875mm - Typhoon Nora (1973)
877mm - Typhoon Ida (1958)
880mm - Typhoon Kit (1966)
880mm - Typhoon Rita (1978)
880mm - Typhoon Vanessa (1984)
880mm - Hurricane Patricia (2015)

The 1970s were a bad decade for storms in the West Pacific.

This is a small fast storm

[trout007]

The hurricane force winds only extend about 25 miles which is way below the average of 100 miles. Katrina was around 125 miles. So while the peak winds here are fast it's a very small storm. Almost midway between a hurricane and tornado.

Re:I've yet to see mention..

[jblues]

..of the potential for flooding in Mexico City. Also, what kind of damage does a 50mph wind do to a shanty-town?

Here's the classification system that we use in the Philippines, where there on average 20 Typhoon's (your Hurricane's eastern twisted sister) per year. It describes the predicted effect at different intensity grades on builds ranging from very light to heavy construction materials. Note that metric units are used.