Tropical Storm Gilma Forecast Discussion

000
WTPZ42 KNHC 190240
TCDEP2

Tropical Storm Gilma Discussion Number   3
NWS National Hurricane Center Miami FL       EP072024
800 PM MST Sun Aug 18 2024

Gilma continues to battle easterly shear this evening.  
Deep convection has been regularly pulsing near the center and 
then pulled off toward the western side of the circulation.  
Subjective Dvorak estimates from TAFB and SAB were T3.0/45 kt and 
T2.0/30 kt, respectively.  Objective intensity estimates range from 
30 to 38 kt.  The initial intensity is held at 35 kt, representing a 
blend of the various estimates.

Strong-to-moderate deep vertical wind shear is forecast to persist 
for the next day or two.  Global models vary when the shear will 
relax, but sometime on Tuesday or Wednesday Gilma should be in a 
more conducive environment and gradually strengthen.  By the end of 
the forecast period, the storm is expected to move into a drier 
airmass with increasing upper-level winds, which should induce 
gradual weakening.  The latest intensity forecast is very similar to 
the previous prediction, slightly higher than the various consensus 
aids.

Gilma is moving westward along the south side of a mid-level ridge 
at 280/11 kt.  A westward to west-northwestward motion should 
continue for the next couple of days.  By Wednesday, Gilma is 
expected to slow down and turn more northwestward when a trough 
off of the west coast of the United States erodes the ridge.  There 
is quite a bit of model spread during this period, with the GFS 
showing a slower forward speed and a more poleward turn compared to 
some of the regional models which stay farther to the south and 
move faster.  The official track forecast lies near the simple 
consensus aids and is slightly south of the previous track through 
60 h and a little to the north afterwards. 


FORECAST POSITIONS AND MAX WINDS

INIT  19/0300Z 14.8N 113.5W   35 KT  40 MPH
 12H  19/1200Z 15.2N 115.2W   40 KT  45 MPH
 24H  20/0000Z 15.5N 117.3W   40 KT  45 MPH
 36H  20/1200Z 15.8N 119.2W   45 KT  50 MPH
 48H  21/0000Z 16.3N 120.7W   50 KT  60 MPH
 60H  21/1200Z 17.1N 122.5W   55 KT  65 MPH
 72H  22/0000Z 17.5N 123.5W   60 KT  70 MPH
 96H  23/0000Z 18.3N 125.5W   70 KT  80 MPH
120H  24/0000Z 19.1N 127.8W   65 KT  75 MPH

$$
Forecaster Bucci