Hurricane Gilma Forecast Discussion

000
WTPZ42 KNHC 242036
TCDEP2

Hurricane Gilma Discussion Number  26
NWS National Hurricane Center Miami FL       EP072024
1100 AM HST Sat Aug 24 2024

Gilma has become better organized during the past few hours, with
the eye becoming more distinct and the eyewall convection becoming
colder and more symmetric.  In response, the various satellite
intensity estimates have increased to the 90-105 kt range.  Based
on that, the initial intensity is increased to 95 kt, and this
might be conservative.  This intensification could be due to the
center passing near a tongue of warmer sea surface temperatures.

The initial motion remains 275/8 kt.  A mid-level ridge is forecast
to gradually build to the north of Gilma during the next several
days, and this should steer the cyclone on a generally westward, or
just north of westward, track through the forecast period.  The
track guidance has changed little since the last advisory, and
while there is some spread in the forward speed it is tightly
clustered in direction.  The new forecast track therefore has
little change from the previous forecast.

In contrast to the track forecast, the intensity forecast and
guidance have significant changes.  First, it is uncertain how long
the current re-intensification will last.  The bulk of the
intensity guidance shows little additional strengthening, but given
that the organization is still increasing some additional
strengthening is possible in the next 6-12 h.  Second, there have
been some changes to the guidance in the 3-5 day period. The
regional hurricane models are forecasting lower intensities than
they did 6 h ago, with only the HAFS-A still keeping Gilma a
tropical storm at 120 h. On the other hand, simulated satellite
imagery from the GFS/ECMWF suggests that the cyclone will continue
to develop organized convection for a longer time than the previous
model runs were forecasting. Putting all of these changes together,
the new intensity forecast calls for a stronger Gilma during the
first 60 h, and now calls for the cyclone to retain tropical storm
status through 96 h. By 120 h, westerly shear and dry air
entrainment should cause the system to degenerate to a remnant low
pressure area.


FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 17.7N 130.9W   95 KT 110 MPH
 12H  25/0600Z 17.8N 132.2W   95 KT 110 MPH
 24H  25/1800Z 18.0N 133.9W   85 KT 100 MPH
 36H  26/0600Z 18.2N 135.7W   75 KT  85 MPH
 48H  26/1800Z 18.4N 137.5W   70 KT  80 MPH
 60H  27/0600Z 18.6N 139.5W   60 KT  70 MPH
 72H  27/1800Z 18.9N 141.6W   55 KT  65 MPH
 96H  28/1800Z 19.5N 145.8W   40 KT  45 MPH
120H  29/1800Z 20.2N 150.3W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven