Sunday, July 28, 2013

Tropical Wave Dorian Attempting to Re-Strengthen

Tropical wave Dorian (now classified as invest 91) is attempting to make a comeback, as overnight developments and new model guidance suggests we are not finished with Dorian just yet.

Satellite imagery above shows a recent sustained burst of convection around Dorian. This convection is evident by the persistent red and orange colors on the satellite loop above. In recent satellite scans, it would appear this convection is weakening, but the fact that this tropical wave has gathered itself after a collapse from tropical storm status is impressive.

A pass from the ASCAT system, which determines wind speed and direction via satellite, has found the tropical wave with a better developed center than what it had about 12 hours ago. This is no major circulation by any means, but it is clear that there is a center associated with Dorian- whether it continues to refine itself is to be determined, but I have little doubt that the increasing convection and better-defined center of circulation spells an impending strengthening of the tropical wave.

Track and intensity guidance has the tropical wave moving northwest in coming days before making a curve north, possibly hitting Florida in the process. The atmospheric flow for this tropical wave is supportive of a track curving north further out to sea, although as of 24 hours ago, the majority of the GFS Ensemble members favored a Gulf of Mexico track. All models pictured here indicate the invest will restrengthen into a tropical storm in just 24 hours, with all but one model projecting hurricane-status strength by the 96 hour mark. The invest will continue to move over relatively warmer waters than what it was over when Dorian had achieved tropical storm status, but it will also be moving through rather substantial shearing.

I think we will see Dorian reform into a tropical storm, but hurricane status is a little out of the realm of reason, in my opinion.


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