Tropical Threat Eases Gulf Coast – Super Typhoon Usagi Threatens Taiwan
Thursday afternoon, September 19th
* Tropical storm risk diminishes in the Gulf of Mexico. 60% probability that disturbance in Bay of Campeche will grow into Tropical Storm Jerry, but latest models keep this storm in a weakened state over the southwestern Gulf of Mexico, more of a threat to Mexico than Texas or the Gulf Coast.
* Super-Typhoon Usagi (Category 5 hurricane) to pass north of the Philippines – poses considerable risk to Taiwan within 48 hours.
A Disorganized Swirl. Latest satellite images show a greatly weakened storm over the Bay of Campeche – no strong strengthening expected today, but there’s still a better than 50/50 chance that this tropical depression will strengthen into Tropical Storm Jerry in the next 48 hours – greatest potential for flooding and (minor) storm surge problems over Mexico. The heaviest rains should stay south of Texas.
Latest Numbers. According to NOAA NHC there is now a 60% risk that a tropical depression will strengthen into Tropical Storm Jerry, down from 70% at this time yesterday. An area of disturbed weather east of the Bahamas is being monitored, with only a 20% chance of tropical storm formation. Humberto poses no risk to the USA.
Latest Model Ensemble. The majority of models (including the European ECWMF) keep “Jerry” as a weak tropical storm, pushing flooding rains into the east coast of Mexico. Heavy rain bands may brush the Brownsville, Texas area with some 1-3″ rains, where minor flash flooding can’t be ruled out. The risk of a strike on the Gulf Coast in the foreseeable, forecastable future (next 3-7 days) has dropped significantly in the last 24 hours.
Night And Day. Yesterday NOAA’s HWRF model, the same one that brought a potential hurricane into the Florida Panhandle by Sunday night during Wednesday’s 12z model run, now shows a greatly weakened system meandering over the far western Gulf of Mexico. The risk to the USA coastline next week isn’t zero, but the odds of a major storm impacting the Gulf Coast is much less than it was yesterday at this time.
Extended Risk of Flash Flooding Along Gulf Coast, Deep South and Pacific Northwest. Although “Jerry” is fizzling, tropical moisture fueling an eastbound cool front will spawn some very heavy rains along the Gulf Coast, with the greatest potential for 4-5″ rains capable of flash flooding from near New Orleans to Pensacola and Tallahassee. A slow-moving Pacific storm may drop over 4″ of rain on Seattle and Tacoma by Tuesday of next week, sparking scattered flooding issues.
Super-Typhoon Usagi. We’re tracking a very intense typhoon (same thing as a hurricane) over the western Pacific, capable of major damage. The storm is forecast to intensify into a Category 5 storm with 150 mph+ winds, then weakening to Category 4 status as it brushes southern Taiwan, where extensive storm surge flooding and inland mudslides may result within the next 48 hours. Manila should avoid serious problems, but some flooding may extend into Taipei as Usagi pushes toward mainland China.
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