Tropical Storm Gordon Discussion Number  12
NWS National Hurricane Center Miami FL       AL072024
500 AM AST Sat Sep 14 2024

The center of Gordon appears to be racing out ahead of the deep 
convective mass to its east in recent proxy-visible satellite 
images. This appearance is consistent with moderate deep-layer 
westerly shear over the cyclone as indicated by model soundings. 
Earlier scatterometer data showed the extent of tropical-storm-force 
winds was about 100 n mi in the northern semicircle of the storm. 
The circulation on the southwest side of the storm was not as well 
defined, with relatively weak winds and signs of elongation. A blend 
of the latest subjective TAFB/SAB Dvorak estimates and objective 
estimates from UW-CIMSS support an initial intensity of 40 kt, which 
is also consistent with the scatterometer winds.

The sheared storm is moving into a drier and more stable air mass, 
which is likely to induce some weakening during the next couple of 
days. In fact, some models continue to show the possibility of 
Gordon losing organized convection and degenerating to a remnant 
low. The official NHC forecast brings Gordon to a depression in 24 h 
but maintains it as a tropical cyclone for now. Environmental 
conditions should become less hostile by the middle of next week, 
and the NHC forecast indicates some re-strengthening could occur 
during that time. This part of the forecast remains conservative, 
as there are still several dynamical models that show little, if 
any, re-intensification later next week.

Gordon appears to be moving west-northwestward (285/8 kt), but a 
gradual turn toward the west and west-southwest is forecast over 
the next couple of days, in good agreement with the latest track 
guidance. Track forecast confidence decreases at days 3-5, where 
the motion appears more sensitive to whether or not Gordon 
restrengthens. A weakness in the mid-level subtropical ridge is 
forecast to develop, which would allow the system to gain some 
latitude if its vertical depth matches that steering level. 
However, a shallower system could continue moving slowly westward 
within the low-level flow. The updated NHC forecast shows a more 
gradual turn toward the northwest and north at days 3-5, in best 
agreement with the TVCA simple consensus aid.


FORECAST POSITIONS AND MAX WINDS

INIT  14/0900Z 20.1N  40.9W   40 KT  45 MPH
12H  14/1800Z 20.0N  42.4W   35 KT  40 MPH
24H  15/0600Z 19.9N  44.1W   30 KT  35 MPH
36H  15/1800Z 19.7N  45.6W   30 KT  35 MPH
48H  16/0600Z 19.5N  46.9W   30 KT  35 MPH
60H  16/1800Z 19.3N  48.4W   30 KT  35 MPH
72H  17/0600Z 19.2N  49.7W   30 KT  35 MPH
96H  18/0600Z 19.5N  51.0W   35 KT  40 MPH
120H  19/0600Z 21.0N  51.5W   40 KT  45 MPH

$$
Forecaster Reinhart