It’s been quite a year for tropical cyclones globally. After several years in a row with few intense hurricanes and typhoons, 2015 has seen a remarkable turnaround. The latest is Patricia, now poised to strike Mexico near Manzanillo later today, and it is about as intense as they come.
There is not much I can say in terms of preparedness actions. Simply put, people in the path of this hurricane need to leave, period. If they haven’t done so already, they need to get moving. That being said, there’s actually some good news.
Patricia is NOT a 100 mile wide or 60 mile wide EF-5 tornado. I’ve seen people saying this on social media and it’s just wrong. Let me explain…
A hurricane like Patricia is very rare, obviously. One thing we do know because of the recon flights that have provided incredible in-situ data is that the radius of maximum winds (RMW) is very narrow. In fact, the ENTIRE extent of hurricane force winds, 74 mph to 200 mph in this case, is ONLY 30 miles from the eye. This is extremely important because it limits the amount of real estate that will have to deal with those winds. In other words, if you live just 40 miles from the eye, you would hardly notice as the core passed by. Move 20 miles closer to the eye and it’s a terrifying siege of flying debris and flesh-stripping wind. So while it will be awful for those who have to endure the core, it’s not like we’re talking about 100 miles of coastline laid to waste.
Another aspect of the small RMW is the storm surge. Katrina had a storm surge of 28+ feet in some locations due to its enormous RMW – more than 90 miles at one point. The result was a surge of water pushed onshore from Louisiana to Florida. In the case of Patricia, it will be a small area, maybe 10 to 20 miles, that receives a possible catastrophic storm surge. Wind drives the surge and the wind is only 200 mph very close to the eye.
I bring this up because it is important to keep the facts straight and not let the historic moment become clouded with information that is simply incorrect. Patricia is bad enough on its own and for those who remain in its path, today will be one not soon forgotten.
Texas to receive Patricia remnants
What happens after Patricia makes landfall? First, it will weaken extremely fast over the higher terrain of interior Mexico. Sadly, there will be potential for loss of life due to the flash flooding and mudslides as the torrents of rain impact those same mountains.
Info-graphic concerning the threat to parts of Texas from the remnants of hurricane Patricia
Interestingly, it looks as though the low level center will be stripped away but the mid and upper level energy will remain fairly intact. This means that there is a slim chance that once the remnants reach the warm Gulf of Mexico, some regeneration could take place. While this is NOT being forecast by the NHC right now, it would not surprise me to see it happen over the weekend or on Monday. What is more likely to happen is that Patricia’s energy leads to more of a non-tropical low pressure area to develop and bring gale force winds and extremely heavy rains to a large part of Texas. All of this will combine with a frontal boundary draped across the region and will help to focus the moisture feed, dumping excessive rain over a large swath of Texas.
In addition to the rain, coastal flooding is a real possibility with the strong onshore flow that is forecast to develop. Water levels could rise several feet in typical flood-prone areas away from the Galveston Seawall. In short, Patricia will leave a mark, even if only indirectly, long after its historic landfall in Mexico.
I will have a video discussion posted this afternoon that will highlight the landfall of Patricia and what to expect after tonight for Texas and vicinity.
M. Sudduth 9:40 AM ET Oct 23