Issued at 1500 UTC TUE AUG 20 2024
Category: Weather
TROPICAL STORM GILMA
Tropical Storm Gilma Forecast Discussion
Issued at 200 AM PDT Tue Aug 20 2024
000 WTPZ42 KNHC 200840 TCDEP2 Tropical Storm Gilma Discussion Number 8 NWS National Hurricane Center Miami FL EP072024 200 AM PDT Tue Aug 20 2024 Gilma continues to struggle with moderate to strong northeasterly vertical wind shear. The center is exposed more than 30 n mi to the northeast of the main convective overcast area. A 20/0129 UTC SSMIS pass and a pair of more recent ASCAT passes were helpful in placing the center well outside of the convective area. The highest reliable ASCAT vectors were only about 40 kt. UW-CIMSS objective intensity estimates range from 34-42 kt. Subjective current intensity estimates from TAFB and SAB were T-3.5/55 kt and T-3.0/45 kt from SAB. Based on the degraded structure on satellite imagery, the ASCAT data and the objective intensity estimates from UW-CIMSS, the initial intensity is set to 45 kt for this advisory. The aforementioned microwave and ASCAT data indicate that the center of the cyclone is a bit farther north than previously estimated. It appears that Gilma has slowed down, and the motion is estimated to be west-northwestward, or 295/7 kt. A mid-level ridge to the north of Gilma should steer the cyclone generally west-northwestward at a similar forward speed through the forecast period. Although the track guidance is gradually coming into better agreement, there is still more spread than normal among the various track aids. The official track forecast is quite similar to the previous NHC track prediction. The NHC forecast track is closer to the ECMWF model than the GFS model through 72 h, and is close to an average of those two models beyond 72 h. Moderate to strong northeasterly vertical wind shear will continue to affect Gilma for another 12 h or so. The SHIPS guidance indicates that the cyclone will reach a much lower wind shear regime by 24 h. Therefore, little change in strength is expected during the next 12-24 h, following by steady intensification. The official intensity forecast was lowered in the short term due to the weaker initial intensity. However, the guidance has become more aggressive after the cyclone reaches the weaker shear, and the NHC forecast follows suit, now showing a peak of 85 kt in 60-72 hr. The new NHC intensity forecast is near the middle of the guidance envelope, in between the weaker statistical guidance and the stronger regional hurricane model dynamical guidance. SSTs along Gilma's path should decrease to about 26C in 72 h, and remain at that value through 96 h before dropping to below 26C. Weakening is forecast during that time period. FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 15.7N 118.3W 45 KT 50 MPH 12H 20/1800Z 16.0N 119.8W 45 KT 50 MPH 24H 21/0600Z 16.4N 121.5W 50 KT 60 MPH 36H 21/1800Z 16.8N 123.0W 60 KT 70 MPH 48H 22/0600Z 17.3N 124.2W 70 KT 80 MPH 60H 22/1800Z 17.7N 125.3W 85 KT 100 MPH 72H 23/0600Z 18.2N 126.4W 85 KT 100 MPH 96H 24/0600Z 19.0N 128.6W 75 KT 85 MPH 120H 25/0600Z 20.0N 131.2W 60 KT 70 MPH $$ Forecaster Hagen/Pasch
Tropical Storm Gilma Wind Speed Probabilities
Issued at 0900 UTC TUE AUG 20 2024
Tropical Storm Gilma Public Advisory
…GILMA CONTINUES TO BATTLE STRONG WIND SHEAR…
As of 2:00 AM PDT Tue Aug 20
the center of Gilma was located near 15.7, -118.3
with movement WNW at 8 mph.
The minimum central pressure was 1000 mb
with maximum sustained winds of about 50 mph.
Hurricane Ernesto Forecast Discussion
Issued at 500 AM AST Tue Aug 20 2024
Tropical Storm Gilma Forecast Advisory
Issued at 0900 UTC TUE AUG 20 2024
Hurricane Ernesto Public Advisory
…ERNESTO MOVING RAPIDLY AWAY FROM NEWFOUNDLAND… …DANGEROUS BEACH CONDITIONS CONTINUING ALONG THE NORTHEAST U.S. COAST AND ATLANTIC CANADA…
As of 5:00 AM AST Tue Aug 20
the center of Ernesto was located near 47.3, -50.0
with movement NE at 36 mph.
The minimum central pressure was 975 mb
with maximum sustained winds of about 75 mph.
Hurricane Ernesto Forecast Advisory
Issued at 0900 UTC TUE AUG 20 2024
Hurricane Ernesto Public Advisory
…DANGEROUS BEACH CONDITIONS CONTINUING ALONG THE NORTHEAST U.S. COAST AND ATLANTIC CANADA… …ERNESTO PASSING SOUTH OF SOUTHEASTERN NEWFOUNDLAND…
As of 11:00 PM AST Mon Aug 19
the center of Ernesto was located near 45.7, -53.1
with movement NE at 35 mph.
The minimum central pressure was 973 mb
with maximum sustained winds of about 80 mph.