Debby Likely to Form Today

   Posted by Levi at 6:55pm on June 23, 2012

We are still watching invest 96L in the central Gulf of Mexico for development into Tropical Storm Debby, which should occur sometime later today. A recon plane is currently investigating 96L to see if the circulation has become defined enough to call it a tropical storm. You can follow live recon data on my recon plotting page throughout the next few days. The center of 96L is still exposed as convection is being sheared to the east by an upper low in the NW gulf. However, this upper low will be backing southwestward towards Mexico over the next couple of days, and a southwestward-moving upper low in the face of a tropical system to its east is usually a favorable or at least improving situation, and thus I expect wind shear will relax somewhat over 96L during the next 48-72 hours, probably not entirely, but enough to allow further gradual organization.

96L will be stalling southeast of New Orleans for the next day or two deciding which way to go. The models are amazingly still split on the track even though the fork in the road is already upon us. That is how close the ridge/trough setup to the north of this system is, and the computers still don’t agree on which feature will capture the storm and steer it. Due to the setup with two troughs, one on each coast of the U.S., and the known northeastward feedback bias that the GFS has, I still believe 96L will eventually get caught underneath the Texas ridge and be brought westward into the NW gulf of Mexico, a solution still supported by the ECMWF, UKMET, and some of the hurricane models. However, until the models reach a consensus, either my track or some other track, the other possibilities cannot be discounted, and the NE gulf coast should still be wary of a possible tropical cyclone landfall during the next few days. Regardless of where 96L ultimately decides to go, heavy rains and tropical storm-like conditions will spread over parts of Florida and the north gulf coast during the next couple of days.

If 96L ends up moving northeastward into Florida, conditions don’t seem likely to allow intensification into a hurricane, and a moderate-strong tropical storm would seem most probable in that scenario. However, if 96L does move westward towards Texas as I expect, the length of time over water and slightly improved upper-level environment could allow strengthening into a hurricane, but that is still several days away, and we will know more once 96L finally picks a track.

Overall, this is a classic early-season development that is taking its time organizing as a sheared system, but there is potential for a stronger storm to develop if it can consolidate the large amount of energy in the Gulf of Mexico. The track remains uncertain, and although my forecast is for a NW gulf coast landfall, the entire gulf coast still needs to monitor this storm closely.

We shall see what happens!

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