Storm Central

Tropical Storm Don Forecast Discussion Number 17

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Issued at 900 AM GMT Tue Jul 18 2023


000
WTNT45 KNHC 180841
TCDAT5
 
Tropical Storm Don Discussion Number  17
NWS National Hurricane Center Miami FL       AL052023
900 AM GMT Tue Jul 18 2023

Convection associated with Don has decreased somewhat in coverage 
and organization over the past several hours, with patches of 
convection now occurring near the center over the northern 
semicircle.  Various subjective and objective satellite intensity 
estimates are in the 30-40 kt range, and these have changed little 
since the previous advisory.  Based on that, the initial intensity 
remains 35 kt.

The initial motion is now 145/10 kt.  The cyclone's motion is 
expected to continue curving clockwise over the next several days as
it is steered by a building mid-level ridge that is forecast to 
shift southwestward to northwestward relative to Don. Eventually 
this ridge will move to the northeast and east of Don, allowing the 
storm to turn northwestward and eventually northward.  One change 
in the guidance since the previous forecast is that it now shows a 
little more westward motion after 36 h than previously, and the new 
track forecast during this time is nudged a little farther to the 
west, There continues to be a significant spread in guidance 
solutions by the end of the forecast period, and the current 
forecast remains low-confidence in that time frame.

Don is currently over sea surface temperatures of about 24C and in 
an area of relatively dry mid-level air. The sea surface 
temperatures along the forecast track increase to 25C during the 
next 72 h, and the cyclone could encounter a more moist air mass 
during that time. Based on this and the intensity guidance, the new 
intensity forecast shows modest intensification during the next 72 
h.  The forecast peak intensity of 45 kt is a compromise between the 
weaker SHIPS/LGEM models and the stronger HWRF/HMON/HAFS models.  
Overall, the new intensity forecast lies near the intensity 
consensus and has only minor adjustments since the previous 
forecast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  18/0900Z 36.3N  39.6W   35 KT  40 MPH
 12H  18/1800Z 35.2N  39.0W   35 KT  40 MPH
 24H  19/0600Z 34.2N  39.1W   35 KT  40 MPH
 36H  19/1800Z 33.8N  39.8W   40 KT  45 MPH
 48H  20/0600Z 33.7N  41.0W   40 KT  45 MPH
 60H  20/1800Z 34.3N  42.3W   45 KT  50 MPH
 72H  21/0600Z 35.2N  44.1W   45 KT  50 MPH
 96H  22/0600Z 38.0N  48.0W   45 KT  50 MPH
120H  23/0600Z 42.0N  49.0W   45 KT  50 MPH
 
$$
Forecaster Beven