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Tropical Storm Don Forecast Discussion



000
WTNT45 KNHC 221445
TCDAT5

Tropical Storm Don Discussion Number  34
NWS National Hurricane Center Miami FL       AL052023
1100 AM AST Sat Jul 22 2023

Don's convective structure has increased in organization this
morning. A curved band has wrapped completely around the center
with a ragged eye-like feature becoming apparent during the past
couple of hours.  Earlier microwave imagery also revealed this
feature, but the convection surrounding it was fragmented.
Subjective satellite estimates from SAB and TAFB were T3.5 (55 kt)
and T3.0 (45 kt) at 1200 UTC, but given the more recent increase in
organization, the initial intensity is raised to the higher end
of those estimates at 55 kt.

Don has made its anticipated northward turn.  A northward motion
with some increase in forward speed is expected today as the
cyclone is steered around the western periphery of a mid-level
ridge.  After that time, Don should turn north-northeastward and
then northeastward within the mid-latitude westerlies.  The
dynamical model guidance remains tightly clustered, and the new NHC
track is essentially an update of the previous advisory.

Don is currently crossing the Gulf Stream with SSTs of around 26C.
Although it is not explicitly shown below, it is possible that some
slight additional strengthening occurs within the next 6-12 hours
while Don is over the slightly warmer Gulf Stream waters.  After
that time, a sharp decrease in SSTs along the track of Don and
increasing vertical wind shear should cause weakening.  Don is
expected to become post-tropical around the 36 hour time period
and dissipate by 72 hours.


FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 39.1N  50.1W   55 KT  65 MPH
 12H  23/0000Z 40.7N  50.0W   55 KT  65 MPH
 24H  23/1200Z 43.3N  48.8W   50 KT  60 MPH
 36H  24/0000Z 45.5N  46.2W   45 KT  50 MPH...POST-TROPICAL
 48H  24/1200Z 46.8N  42.6W   35 KT  40 MPH...POST-TROPICAL
 60H  25/0000Z 48.0N  38.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  25/1200Z...DISSIPATED

$$
Forecaster Brown



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