Tropical Storm Gordon Forecast Discussion

000
WTNT42 KNHC 150238
TCDAT2

Tropical Storm Gordon Discussion Number  15
NWS National Hurricane Center Miami FL       AL072024
1100 PM AST Sat Sep 14 2024

Gordon's surface circulation has become fully exposed this evening 
and is displaced about 150 mi west of the remaining deep convective 
mass.  The deep-layer westerly shear likely has increased during the 
past few hours.  The initial intensity is lowered to 35 kt for this 
advisory and is based on constrained subjective satellite intensity 
T-number estimates from TAFB and SAB.

Based on the statistical GFS/ECMWF SHIPS intensity guidance and 
global model sounding forecasts, Gordon should continue to struggle 
and weaken during the next few days while moving through a harsh 
thermodynamic environment.  In fact, the global models agree that 
the cyclone will become a remnant low toward the end of the week as 
it commences a gradual north-northwestward turn.  For now, the 
surface circulation is expected to remain intact, and Gordon is 
expected to continue moving generally northward, where atmospheric 
conditions could become less hostile.  The official intensity 
forecast shows Gordon maintaining depression strength through day 5 
in deference to the global model and HCCA solutions.  The 
Decay-SHIPS, LGEM, and IVCN intensity aids, however, continue to 
show significant re-strengthening late in the period.  Consequently, 
subsequent advisories may need changes, particularly if the global 
models align more with the intensity aids mentioned above.  

Gordon's initial motion is estimated to be west-southwestward or 
245/9 kt and is steered by a low- to mid-tropospheric ridge 
extending west-southwestward from high pressure over the North 
Atlantic.  Gordon should continue toward the west-southwest or west 
during the next 60-72 hours.  Afterward, a weakness in the 
subtropical ridge over the central Atlantic is forecast in response 
to an amplifying mid- to upper-tropospheric trough.  As the cyclone 
approaches this break in the ridge, the cyclone should gradually 
turn toward the north-northwest by the end of the period.  This 
forecast track scenario once again assumes that the cyclone 
will survive during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT  15/0300Z 19.7N  43.8W   35 KT  40 MPH
 12H  15/1200Z 19.6N  45.4W   30 KT  35 MPH
 24H  16/0000Z 19.5N  47.0W   30 KT  35 MPH
 36H  16/1200Z 19.4N  48.5W   30 KT  35 MPH
 48H  17/0000Z 19.3N  49.7W   30 KT  35 MPH
 60H  17/1200Z 19.3N  50.4W   30 KT  35 MPH
 72H  18/0000Z 19.4N  50.9W   30 KT  35 MPH
 96H  19/0000Z 20.2N  51.4W   30 KT  35 MPH
120H  20/0000Z 22.0N  50.6W   30 KT  35 MPH

$$
Forecaster Roberts