Official Discussion issued by the National Hurricane Center

Don (AL052023) DATA RELEASED: 7/19/2023 3:00:00 PM UTC

Copy of official data

Tropical Storm Don Discussion Number  22
NWS National Hurricane Center Miami FL       AL052023
300 PM GMT Wed Jul 19 2023

Don is becoming better organized this morning.  Satellite images 
indicate deep convection is wrapping closer to the center, with 
good banding features noted in the southern semicircle.  
Additionally, it looks like a smaller core is forming within the 
larger circulation on a 1156 UTC GMI pass, which could help 
insulate the system from environmental dry air.  The initial wind 
speed remains 35 kt in concert with the latest TAFB Dvorak and 
CIMSS ADT estimates.

The stage is finally set for intensification of Don with the 
smaller core forming, along with the storm reaching a maximum in 
SST during the next day or so and encountering light shear.  
Gradual strengthening is shown through tomorrow, consistent with 
the latest guidance and a bit higher the last NHC forecast.  By 
late Thursday, water temperatures begin to cool again, and shear is 
forecast to increase slightly.  This is probably enough to arrest 
significant strengthening across the remainder of the forecast 
period, so the intensity forecast is leveled off through 96 h.  
Interestingly, the guidance has decreased since the last cycle, and 
the model consensus is now within 5 kt of NHC at every time period. 
Weakening should commence after it moves north of the Gulf Stream, 
and the cyclone should become post-tropical sometime on Sunday.

Don has turned west-southwestward, still at about 4 kt.  No 
significant changes were made to the last NHC forecast track as Don 
continues its anticyclonic loop around a blocking ridge in the 
north-central Atlantic.  Similar to yesterday, the ECMWF-based 
guidance is on the right side of the envelope and the GFS-based 
models are on the left side.  The latest corrected-consensus models 
are very close to the last NHC forecast track reasoning, so this 
forecast is essentially just an update of the previous one.


INIT  19/1500Z 33.9N  39.6W   35 KT  40 MPH
12H  20/0000Z 33.7N  40.4W   40 KT  45 MPH
24H  20/1200Z 33.9N  41.8W   45 KT  50 MPH
36H  21/0000Z 34.6N  43.3W   45 KT  50 MPH
48H  21/1200Z 35.7N  45.2W   45 KT  50 MPH
60H  22/0000Z 37.2N  46.9W   45 KT  50 MPH
72H  22/1200Z 39.2N  48.4W   45 KT  50 MPH
96H  23/1200Z 44.0N  47.5W   45 KT  50 MPH
120H  24/1200Z 47.0N  43.0W   35 KT  40 MPH...POST-TROPICAL

Forecaster Blake