Official Discussion issued by the National Hurricane Center

Don (AL052023) DATA RELEASED: 7/16/2023 9:00:00 AM UTC

Copy of official data

Subtropical Storm Don Discussion Number   9
NWS National Hurricane Center Miami FL       AL052023
500 AM AST Sun Jul 16 2023

Don is barely a subtropical storm.  As mentioned in the previous 
discussion, the ASCAT-C pass from around 00Z showed peak winds near 
35 kt in a small area about 60 n mi east-northeast of the center.  
Deep convection is limited to the same region where the strongest 
winds were observed.  The initial intensity remains 35 kt for this 
advisory based on the earlier ASCAT data and a blend of the latest 
satellite intensity estimates that range from 25 to 45 kt.

The storm is currently over cool 24 degree C waters and the sea 
surface temperatures along the expected track over the next day or 
two are about a degree lower.  These unfavorable oceanic conditions 
combined with dry air that continues to wrap into the circulation 
should cause Don to remain poorly organized.  If the storm does 
manage to survive beyond 48-72 hours, the water temperatures are 
expected to increase a little along the forecast track, which could 
cause some increase in thunderstorm activity.  Nonetheless, 
significant strengthening is not expected due to continued dry air 
entrainment and an increase in wind shear.  The NHC intensity 
forecast is similar to the previous one and shows Don remaining a 
weak system through the forecast period.  However, even though not 
explicitly forecast, it would not be surprising if Don becomes a 
remnant low at some point in the next couple of days.  

Don is gradually bending to the right and an eastward motion is 
expected later today as high pressure builds over the eastern 
Atlantic.  A turn to the southeast is expected on Monday followed by 
a southward motion as the ridge shifts westward and a trough becomes 
established over the northeastern Atlantic.  Don could stall or loop 
around during the middle part of the weak as the steering currents 
collapse.  The model guidance has not changed much, and the NHC 
track forecast generally follows the various consensus models.


INIT  16/0900Z 38.6N  48.4W   35 KT  40 MPH
12H  16/1800Z 39.3N  47.6W   35 KT  40 MPH
24H  17/0600Z 39.4N  45.6W   30 KT  35 MPH
36H  17/1800Z 38.6N  43.5W   30 KT  35 MPH
48H  18/0600Z 37.2N  41.8W   30 KT  35 MPH
60H  18/1800Z 35.8N  41.2W   30 KT  35 MPH
72H  19/0600Z 34.3N  41.3W   30 KT  35 MPH
96H  20/0600Z 32.8N  42.6W   35 KT  40 MPH
120H  21/0600Z 33.6N  44.7W   35 KT  40 MPH

Forecaster Cangialosi