07 September 2013

Gabrielle, TD8, and eastern Atlantic disturbance

Since my last update on Thursday, Tropical Storm Gabrielle dissipated due to a combination of shear, dry air, and land interaction with Puerto Rico.  However, the remnants are still very much trackable, and are showing signs of regeneration now that the system is north of Puerto Rico and Hispaniola.

Enhanced satellite image of former Gabrielle.  The center (marked with a red L) is nearly exposed on the northwest side of the deep convection.  The sharp boundary of the high clouds there is indicative of strong vertical shear.  (NOAA)
Though over very warm water (29C), the vertical wind shear is up near 30kts and is not expected to relax in the foreseeable future.  That will be the primary factor in inhibiting its regeneration.  NHC is giving it a 40% chance of formation over the next 5 days, and I would agree with that number... IF it reforms, it would be working against the odds.

The track guidance is all over the place, largely due to the uncertainty in whether or not it regains some sort of organization.  Not all models agree on that, so of course, not all models agree on a similar track. 

Moving on to TD8... if you sneezed, you missed it.  It formed yesterday afternoon in the extreme southwestern Gulf of Mexico, right on the coastline, and then dissipated inland early this morning.  It was never named -- just a short-lived Tropical Depression.

Elsewhere, there is a strong easterly wave located approximately 700 miles west of the Cape Verde islands.  It exited the African coast back on Sept 2.  As you can see below, it's not very well organized at all yet.

Most models bring it N-NW for another day or so, then flatten out to a more W course for several days.  Even in five days, it will still be short of the Lesser Antilles, so there is time to see how this one evolves.  I'll add additional details in a future post, but for now, it's at least worth pointing out.

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