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Tropical Storm Margot Discussion Number  37
NWS National Hurricane Center Miami FL       AL142023
300 PM GMT Sat Sep 16 2023
 
Margot's structure has continued to degrade, with the low level 
center now exposed on visible satellite imagery. Deep convection is 
mainly limited to the southern semicircle of the tropical storm. Dry 
air is also wrapping around the western and southern side of Margot. 
The subjective Dvorak intensity estimates from TAFB and SAB both 
support an initial intensity of 45 kt.

Margot has maintained its southwestward heading and is moving 
slightly faster, with an initial estimate of 215/7 kt. Since the 
tropical storm has yet to turn due west, the official forecast shows 
a slightly larger clockwise loop around a mid-level ridge through 48 
hours. This is on the eastern edge of the model consensus aids. As 
the mid-level ridge builds south-eastward, Margot is expected to 
turn back towards the east and potentially interact with a shortwave 
trough arriving from the northwest. Beyond 48 hours, the NHC 
forecast is slightly south of and slower than the previous forecast, 
closest to the HCCA consensus aid.

Environmental conditions are not expected to improve, with 
moderate-to-strong northerly vertical wind shear, dry mid-level 
relative humidities, and sea surface temperatures of 26 Celsius or 
less through the forecast period. As a result, weakening is forecast 
in the near-term, and simulated satellite IR imagery from the GFS 
and ECMWF shows a notable lack of deep convection during this time. 
By Monday night, Margot is expected to begin interacting with a 
mid-latitude shortwave trough. This could allow for some slight 
re-intensification, as is shown in the official forecast. Margot is 
not expected to be absorbed by the trough and is forecast to 
degenerate into a post-tropical cyclone west of the Azores.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/1500Z 34.4N  38.7W   45 KT  50 MPH
 12H  17/0000Z 34.1N  40.1W   40 KT  45 MPH
 24H  17/1200Z 34.3N  41.7W   35 KT  40 MPH
 36H  18/0000Z 35.1N  43.0W   35 KT  40 MPH
 48H  18/1200Z 36.5N  42.9W   35 KT  40 MPH
 60H  19/0000Z 37.9N  40.9W   40 KT  45 MPH
 72H  19/1200Z 38.6N  37.8W   40 KT  45 MPH
 96H  20/1200Z 37.8N  33.1W   30 KT  35 MPH...POST-TROPICAL
120H  21/1200Z 38.0N  30.1W   30 KT  35 MPH...POST-TROPICAL
 
$$
Forecaster Mahoney/Bucci
 
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