12 September 2006

Florence still a hurricane, Gordon and TD8 form...

Florence is now a minimal hurricane, and beginning an extratropical transition... still a warm-core cyclone, but the wind field is expanding, convection has departed the inner core, and it's becoming asymmetric.  The latest advisory has the intensity at 65kts and 982mb, and moving NE at 20kts.

At 21Z yesterday, TD7 was upgraded to TS Gordon, and it's now a 50kt storm, on the way to becoming the season's third hurricane.  Currently located near 23N 58W, it's forecast to more or less follow in Florence's footsteps and recurve to the north by 60W, safely to the east of Bermuda this time.  It should reach hurricane strength, but probably not have time for much more than that before increasing wind shear takes its toll.  Gordon is a compact storm, so in the near future, rapid intensity changes are not out of the question.

At 15Z today, the well-organized wave I mentioned immediately off the African coast was upgraded to TD8, just southeast of the Cape Islands at 12.5N 23W.  The satellite presentation is truly remarkable for a storm so far east, and the likelihood of it being upgraded to TS Helene later today is high.  The future should be just a general WNW track over the next 5+ days, with the potential for significant development.  The initial intensity is 25kts and 1007mb.  It's still close enough to land and a major field program that it will have some aircraft recon and dropsondes at this early phase of development... how exciting!  The vertical shear is forecast to remain VERY low over the next 5 days, with SSTs around 27.5-28.5C.
Coincidentally, this storm has a LOT in common already with Hugo '89 in terms of early genesis, African coastal exit location and date, etc.

Please visit my tropical Atlantic headquarters.

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