Gustav - Thursday update

Due to land interactions with Haiti over the last 48 hours, the center of Gustav has reformed overnight nearly 100 miles to the SSW of its previous location. Hurricane warnings have been posted for Jamaica - and Gustav is forecasted to cross the island today as a borderline Category 1 hurricane.

The speed at which Gustav has restrengthened and reorganized after interaction with Haiti is impressive. As I said yesterday afternoon, not too long ago (18hrs) it was very difficult even to locate the exact center. This is a perfect example of how, when the right conditions are present - low wind shear, plenty of moist air, and very warm ocean temperatures - rapid intensification is always possible. The right conditions are forecasted to remain with Gustav more or less the entire way to the Central Gulf Coast early next week.

My updated forecast will be for Gustav to stay mostly toward the southern side of Jamaica - where effects from land interaction should push the convection - and rapidly intensify once it clears the island, sometime tomorrow. From there, a passage over the Cayman islands and through the Yucatan Channel between Mexico and the Western tip of Cuba and into the southern Gulf of Mexico. As I said yesterday, the warmest waters in the entire Atlantic exist along this route, and should promote the development of a major hurricane in the Gulf this weekend.

Uncertainty still exists in the final landfall area on the US Gulf Coast - as landfall is still 5 days away. We'll have to closely watch how Gustav interacts with Jamaica - but Jamaica should be the last major disruption before Gustav enters the Gulf. I don't know how intense Gustav will ultimately become in the Gulf - between Category 3 and 5 - but I am still predicting a Category 3 landfall. I'm shifting the final landfall location a bit west - to agree with the latest model consensus and trends - to between the TX/LA border and Grand Isle, LA.

Yesterday, Louisiana Governor Bobby Jindal declared a state of emergency and activated 5000 National Guard personnel - hopefully the first step in a well ordered preparation and evacuation process. As the Times-Picayune has mentioned, this evacuation has the potential to be much larger than Katrina for Louisiana - as the landfall will be to the west - necessitating the evacuation of nearly all of southern Louisiana.

What's more - a new tropical storm - Hanna - also formed overnight. It's in the central Atlantic, forecasted to strengthen to a hurricane in 3 days - and stall out halfway between the Bahamas and Bermuda. About equal chances right now of it getting picked up by a cold front or remaining behind as a threat to the east coast next week. Stay tuned.


Probability of Tropical Storm force winds from Gustav and Hanna the next 5 days.