ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Gilma Discussion Number 6
NWS National Hurricane Center Miami FL EP072024
200 PM PDT Mon Aug 19 2024
ASCAT data valid at 1644 UTC showed that Gilma has strengthened
slightly and its wind field has grown a little. While the tropical
storm is still sheared, maximum winds measured by the ASCAT were
between 40 and 45 kt, which after accounting for undersampling
supports an intensity around 50 kt. An average of the most recent
Dvorak estimates from TAFB and SAB also yields 50 kt, so that is the
intensity estimate for this advisory. The maximum extent of 34 kt
winds is estimated to be around 70 n mi based on the ASCAT data,
mostly to the southwest in the deep convection.
Although the track forecast spread in the model guidance remains
unusually high, not much change was made to the NHC forecast, except
to show a slightly faster forward motion in 24-48 h. Otherwise,
Gilma is still expected to slow down and turn west-northwestward
within the next day as the ridge currently steering the storm is
gradually eroded by a deep-layer trough off the U.S. west coast.
There is still quite a bit of difference between the models in the
forward speed of Gilma, so the NHC forecast closely follows the
consensus throughout the forecast.
Only small adjustments were made to the intensity forecast. Gilma
should remain sheared for another day or so, limiting the potential
for strengthening during that period. After that, the shear should
decrease and Gilma should strengthen. Most models continue to
indicate that Gilma will approach hurricane strength later this
week. The NHC intensity forecast remains very close to the various
intensity consensus aids.
FORECAST POSITIONS AND MAX WINDS
INIT 19/2100Z 15.1N 116.9W 50 KT 60 MPH
12H 20/0600Z 15.5N 118.2W 55 KT 65 MPH
24H 20/1800Z 16.2N 120.0W 55 KT 65 MPH
36H 21/0600Z 16.7N 122.0W 55 KT 65 MPH
48H 21/1800Z 17.2N 123.6W 60 KT 70 MPH
60H 22/0600Z 17.8N 124.7W 70 KT 80 MPH
72H 22/1800Z 18.3N 126.0W 75 KT 85 MPH
96H 23/1800Z 19.0N 127.5W 75 KT 85 MPH
120H 24/1800Z 20.0N 130.0W 65 KT 75 MPH
$$
Forecaster D. Zelinsky
NNNN