[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT43 KNHC 220237
TCDAT3

Tropical Storm Gaston Discussion Number   7
NWS National Hurricane Center Miami FL       AL082022
300 AM GMT Thu Sep 22 2022

Convective bursts continue near the center of Gaston with some
banding evident over the western portions of the circulation. Dvorak
CI-numbers from SAB and TAFB still support an initial intensity of
55 kt.  Unfortunately, ASCAT missed the system earlier, and there
has been no recent scatterometer data to provide a better assessment
of the system's strength and wind field.

Gaston as turned east-northeastward and is not moving at 065/15 kt.
The overall track forecast reasoning remains unchanged but there
has been a shift in the models toward a faster and more southerly
track, primarily after 48 hours. The cyclone should continue
east-northeastward to eastward during the next day or so.  After
that time, an amplifying ridge is expected to cause Gaston to slow
down and turn southward.  After 48 hours, the track guidance now
shows a faster southwestward or westward motion as the ridge builds
and shifts northeastward.  The updated NHC track has been adjusted
accordingly, but it is still north of the latest consensus aids.
Therefore, additional modifications to the official forecast is
possible in future advisories.

Little change in strength is predicted in the short term, but
gradual weakening is expected after that time as Gaston moves over
cooler waters and into a drier air mass. Gaston is likely to become
a post-tropical cyclone in 60-72 hours due to these more
unfavorable conditions.

Gaston could produce tropical-storm-force winds in portions of the
western Azores beginning tonight.  Interests there should continue
to monitor the forecasts for this system.  For additional
information, see warnings and products issued by the meteorological
service in the Azores.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 39.6N  38.0W   55 KT  65 MPH
 12H  22/1200Z 40.4N  35.0W   55 KT  65 MPH
 24H  23/0000Z 40.8N  31.9W   55 KT  65 MPH
 36H  23/1200Z 40.3N  29.9W   50 KT  60 MPH
 48H  24/0000Z 39.4N  29.4W   45 KT  50 MPH
 60H  24/1200Z 38.9N  30.3W   45 KT  50 MPH...POST-TROPICAL
 72H  25/0000Z 38.8N  31.8W   40 KT  45 MPH...POST-TROPICAL
 96H  26/0000Z 39.0N  35.7W   35 KT  40 MPH...POST-TROPICAL
120H  27/0000Z 38.7N  38.6W   30 KT  35 MPH...POST-TROPICAL

$$
Forecaster Brown
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