Tropical Storm Gordon Forecast Discussion

297 
WTNT42 KNHC 140240
TCDAT2

Tropical Storm Gordon Discussion Number  11
NWS National Hurricane Center Miami FL       AL072024
1100 PM AST Fri Sep 13 2024

A 13/2045 UTC CSA RADARSAT Constellation Mission VH polarization 
image indicated that Gordon's surface center was farther east than 
previously indicated.  Subsequently, the surface center has become 
more obscured while the convective mass has expanded somewhat over 
the western portion of the cyclone.  A blend of the subjective 
Dvorak satellite intensity estimates from TAFB and SAB yields an 
intensity of 40 kt for this advisory.

Although the statistical SHIPS intensity guidance shows the westerly 
shear gradually diminishing through the period, the dry, stable 
thermodynamic surrounding environment is expected to be the primary 
inhibiting parameter. Gordon could degenerate to a remnant low 
around mid-period, although not shown explicitly in the NHC 
forecast.  Beyond day 3, the official forecast shows gradual 
re-strengthening while atmospheric conditions become less hostile.  
The NHC intensity forecast is similar to the previous advisory and 
based on the IVCN intensity consensus and below the Decay SHIPS 
statistical guidance.

Gordon's initial motion is estimated to be westward or 280/8 kt
and is steered by a low- to mid-tropospheric ridge extending
west-southwestward from high pressure over the Azores.  The cyclone
should continue slowly toward the west to west-southwest during 
the next 72 hours.  Afterward, a break in the subtropical ridge over
the central Atlantic is forecast in response to an amplifying mid-
to upper-level trough.  As Gordon approaches this growing weakness
in the ridge, the cyclone should turn toward the northwest and 
north.  This forecast track scenario, however, assumes that the 
cyclone strengthens toward the end of the period.  Only a slight 
adjustment to the left of the previous forecast beyond day 3 was 
made to lie closer to the TVCN consensus aid.  


FORECAST POSITIONS AND MAX WINDS

INIT  14/0300Z 19.8N  40.3W   40 KT  45 MPH
 12H  14/1200Z 19.9N  41.8W   40 KT  45 MPH
 24H  15/0000Z 19.7N  43.8W   30 KT  35 MPH
 36H  15/1200Z 19.5N  45.2W   30 KT  35 MPH
 48H  16/0000Z 19.4N  46.4W   30 KT  35 MPH
 60H  16/1200Z 19.3N  47.6W   30 KT  35 MPH
 72H  17/0000Z 19.5N  49.1W   30 KT  35 MPH
 96H  18/0000Z 20.1N  50.4W   35 KT  40 MPH
120H  19/0000Z 21.2N  50.7W   40 KT  45 MPH

$$
Forecaster Roberts