Official Discussion issued by the National Hurricane Center

Don (AL052023) DATA RELEASED: 7/18/2023 3:00:00 PM UTC

Copy of official data

Tropical Storm Don Discussion Number  18
NWS National Hurricane Center Miami FL       AL052023
300 PM GMT Tue Jul 18 2023

Don has struggled to produce deep convection today, despite the 
storm moving over warmer waters, with only a few moderate bands on 
the eastern side of the circulation.  A scatterometer pass near 
1200 UTC showed maximum winds just above 30 kt, and it seems like 
the system is vacillating between 30 and 35 kt as an initial wind 
speed, based primarily on convective trends.  I don't really want 
to be chasing every burst of convection, so the conservative thing 
is to wait a little longer before downgrading it to a depression.

The system should not change much in intensity over the next day or 
so while it encounters a slightly more conducive (but still 
marginal) environment.  It also wouldn't be a surprise if Don became 
a depression again in the short-term.  Modest intensification is 
forecast later this week while the system encounters warmer SSTs, 
higher mid-level moisture, and the shear remains light or moderate. 
The new forecast is similar to the previous one, below the model 
consensus given the overall mediocre environment for strengthening.

Don has turned south-southeastward at about 8 kt.  The storm is 
about halfway through making a large anticyclonic loop over the 
central Atlantic, bending around a blocking ridge in the 
mid-latitudes.  Don should move more slowly southward overnight and 
Wednesday as it sits beneath the ridge, then gradually accelerate 
northwestward and northward as it moves around the ridge.  The track 
guidance is coming into better agreement on this course, 
conveniently converging somewhat on the last NHC track forecast, so 
no significant changes were required.  


INIT  18/1500Z 35.6N  39.3W   35 KT  40 MPH
12H  19/0000Z 34.6N  39.0W   35 KT  40 MPH
24H  19/1200Z 33.9N  39.4W   35 KT  40 MPH
36H  20/0000Z 33.7N  40.5W   40 KT  45 MPH
48H  20/1200Z 34.0N  41.7W   40 KT  45 MPH
60H  21/0000Z 34.7N  43.3W   45 KT  50 MPH
72H  21/1200Z 35.7N  45.1W   45 KT  50 MPH
96H  22/1200Z 39.0N  49.3W   45 KT  50 MPH
120H  23/1200Z 44.0N  49.5W   45 KT  50 MPH

Forecaster Blake