Storm Central

Tropical Storm Don Forecast Discussion Number 21

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Issued at 900 AM GMT Wed Jul 19 2023

WTNT45 KNHC 190836
Tropical Storm Don Discussion Number  21
NWS National Hurricane Center Miami FL       AL052023
900 AM GMT Wed Jul 19 2023

Convection associated with Don remains disorganized this morning, 
primarily occurring in a group of short bands in the eastern 
semicircle.  Satellite intensity estimates have not changed much 
since the last advisory, and the initial intensity is held at 35 kt 
in best agreement with the CIMSS satellite consensus.

As Don turns more westward during the next couple of days, it 
should move over warmer sea surface temperatures into a somewhat 
more moist air mass.  This should allow some gradual strengthening, 
and the new intensity forecast follows the previous forecast in 
calling for a 45 kt intensity by 48 h.  It should be noted that 
several of the dynamical models forecast Don to get stronger than 
that, possibly due to them expecting Don to move west of the 
current forecast track into even warmer sea surface temperatures.  
After Don turns northward later in the forecast period, it should 
move north of the Gulf Stream and degenerate to a post-tropical low 
over cold water between 96-120 h.

The initial motion is now 185/4 kt.  Don should turn southwestward 
and westward during the next 24-36 h as the subtropical ridge 
builds to the northwest and north of the cyclone.  This ridge 
should then move eastward, leaving the cyclone in a area of 
southeasterly to southerly flow on its west side.  This should 
allow Don to turn northward by about 72 h and then subsequently 
recurve into the westerlies.  The new forecast track is essentially 
an update of the previous forecast.
INIT  19/0900Z 34.0N  39.3W   35 KT  40 MPH
 12H  19/1800Z 33.7N  40.0W   35 KT  40 MPH
 24H  20/0600Z 33.7N  41.2W   40 KT  45 MPH
 36H  20/1800Z 34.3N  42.7W   40 KT  45 MPH
 48H  21/0600Z 35.1N  44.5W   45 KT  50 MPH
 60H  21/1800Z 36.4N  46.3W   45 KT  50 MPH
 72H  22/0600Z 38.4N  48.2W   45 KT  50 MPH
 96H  23/0600Z 43.5N  48.5W   45 KT  50 MPH
120H  24/0600Z 46.6N  43.5W   35 KT  40 MPH...POST-TROPICAL
Forecaster Beven