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Saturday, October 24, 2015

Hurricane Patricia - stronger than Haiyan

Sou | 1:22 PM Go to the first of 4 comments. Add a comment
It was born and grew so quickly and is being described as the strongest ever tropical cyclone in the western hemisphere. In just 24 hours Patricia grew from a tropical storm to a Category 5 hurricane. It has made landfall in Mexico, with sustained winds (not just gusts) reported at 265 km an hour (165 mph). The ABC reported that before it hit land it had "winds of 325 kilometres per hour, even more powerful than the 315-kilometre-per-hour winds of Super Typhoon Haiyan".

Extra warm seas at some depth


It's intensity is because of the very warm water off the coast of Mexico. It's warm at depth. National Geographic asked scientists:
Scientists don't fully understand why Patricia grew so intense so quickly. But part of the reason is due to an unusually deep pool of warm water off Mexico's Pacific coast, says Kerry Emanuel, an atmospheric scientist at the Massachusetts Institute of Technology.

As a hurricane intensifies, it churns up the ocean beneath it, drawing deeper, colder water to the surface. Since tropical cyclones feed on warm water, that cooler water acts as a kind of brake, limiting how strong most hurricanes get, Emanuel says.

But in Patricia's case, the warm pool of water beneath the storm goes down nearly 200 feet (61 meters). "That makes it harder for the hurricane to churn up cold water," says Emanuel.

That deep blob of warm water could be due to this year's predicted strong El NiƱo, a weather pattern characterized by warmer-than-usual water in parts of the Pacific Ocean.

Given the limitations in understanding the mechanics of hurricanes and the effects of climate change on these storms, Herndon fears Patricia won't be the last nasty surprise we see.

Strong winds


The article also provides some comparisons with Patricia's reported sustained winds of 265 kph, and up to 325 kph before landfall:
Tip's wind speeds topped out at 190 miles (306 kilometers) per hour.
Super Typhoon Haiyan, which struck the Philippines in 2013, recorded pressures as low as 895 millibars with wind speeds of 195 miles (315 kilometers) per hour. Hurricane Katrina came in at 902 millibars with maximum wind speeds of 175 miles (282 kilometers) per hour.

According to NOAA's public advisory, the winds will weaken as they hit the mountains. It warns of rainfall of "8 to 12 inches, with isolated maximum amounts of 20 inches, over the Mexican states of Nayarit, Jalisco, Colima, Michoacan, and Guerrero through Saturday.  These rains could produce life-threatening flash floods and mud slides." In addition there is a warning of storm surges. (I've archived the NOAA public advisory for the record.)

Below is an image of winds taken about 8 hours ago from Earth.nullschool.net:



And just now:



Stay safe.

4 comments:

  1. Bob Tisdale will link Patricia with El Nino and skeptics everywhere, reassured that all is well in their non-science worlds, will breathe a collective sigh of relief.

    ReplyDelete
    Replies
    1. Last time Bob tried to claim that the sea wasn't warm by putting up charts of average sea surface temperature over decades (not days). He may well try it again this time. I don't know what he thinks feeds tropical cyclones.

      Delete
  2. For the flash-enabled, the NHC page of the Saffir-Simpson scale has a great animation.

    http://www.nhc.noaa.gov/aboutsshws.php

    The effects it shows max out at 157 mph. Patricia was stronger than that at landfall -- and much stronger at its peak.

    ReplyDelete
  3. Thanks to a tiny eye, prompt evacuations, and landfall in a sparsely populated area, there seem to have been no deaths and no great damage as a result. Has anyone yet seen denialists chastising the alarmists and warmists and category-fivists for their utterly inaccurate predictions of catastrophe? I certainly expect some.

    ReplyDelete

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