19 September 2002

Isidore quickly organizing, Josephine becomes extratropical.

Tropical Storm Isidore is on the brink of being the second hurricane of
the season.  After a slow start during the weekend and the first half of
this week, the center is finally under the coldest part of the CDO, and
recent microwave imagery shows very clearly that an eye has formed in
the precipitation.  It will be just a matter of hours until that is
reflected in the VIS and IR imagery.

As of 15Z today, Isidore is located at 20.0N 81.2W and moving WNW at
7kts.  maximum sustained winds are 60kts and MSLP is 990mb (which
coincides nicely with the classic pressure for eye development in the
Atlantic).  Aircraft recon will investigate the storm later today, and
given the trend in organization and the microwave imagery showing an
eye/eyewall, they should find 65-70kt winds, making it a hurricane at
that time.  The outflow is expanding in all directions, showing that the
anticyclone aloft is maturing and assisting the "exhaust" process.

A Tropical Storm Warning is still in effect for the Cayman Islands, a
Hurricane Watch is in effect for some of central Cuba, and a Hurricane
Warning is in effect for the western half of Cuba.  It is possible that
a Tropical Storm Warning will be issued for the Florida Keys this
afternoon if the storm's wind field keeps expanding.

The forecast is very difficult, and I'd say that the track forecast is
more challenging than the intensity this time.  Cuba will be the only
hinderance to intensification, and western Cuba is fairly flat, but land
nonetheless.  All other signs point to a major hurricane in a few
days... low shear, very deep, warm ocean to travel over, and time.  The
models are in good agreement about taking it over the western tip of
Cuba, but beyond that, the concensus is to stall it in the southeast
Gulf (with several outliers).  Depending very strongly on what the
trough does that's draped over the central US now, Isidore could end up
hitting anywhere from Mexico to Florida, so everyone along the Gulf
coast needs to be be watchful and prepared.  So far, the track is
reminiscent of Helene '00 (and she hit the western end of the Florida
peninsula), just FYI.

TS Josephine was absorbed by the mid-latitude trough this morning and
advisories have ceased as of 15Z (11am EDT).  The last advisory placed
Josephine at 42.5N 42.5W and tracking NE at 27kts, basically with the
front.  Intensity was 50kts and 1004mb (definite baroclinic

Please visit my tropical Atlantic headquarters.

No comments:

Post a Comment