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Tropical Storm Bret Discussion Number   8
NWS National Hurricane Center Miami FL       AL032023
500 AM AST Wed Jun 21 2023
 
The storm's cloud pattern consists of a ragged-looking CDO with a 
few very cold cloud tops, along with some banding features over the 
eastern semicircle.  The current intensity estimate is set at 50 kt, 
which is the average of subjective Dvorak estimates from TAFB and 
SAB.  Although the overall upper-tropospheric outflow pattern 
remains fairly well defined, the outflow is beginning to become 
slightly impeded over the western portion of the circulation.  An 
Air Force Hurricane Hunter aircraft is scheduled to investigate Bret 
this afternoon, and should provide a better estimate of the storm's 
intensity and structure.

Some additional strengthening is possible during the next day or so, 
but when the cyclone moves into the eastern Caribbean Sea, the 
atmospheric environment is expected to become increasingly 
unfavorable for intensification.  Dynamical guidance indicates that 
the flow associated with an upper-level trough over the eastern 
Caribbean, and a stronger trough farther west, should create a 
significant increase in vertical shear over Bret.  As a result, the 
tropical cyclone is likely to begin weakening in a couple of days, 
and global models are in good agreement that the system will 
degenerate into a wave as it approaches the western Caribbean Sea.  
The official intensity forecast is similar to the previous one and 
near or a little above the model consensus.

Bret continues its mainly westward track with an initial motion of 
280/14 kt.  A mid-level ridge should be maintained to the north of 
the tropical cyclone for the next few days.  This steering pattern 
will maintain a slightly north of due westward movement until the 
system dissipates.  Users are reminded that NHC's track forecasts 
have average errors of about 60 n mi at 48 hours, and it is too soon 
to know exactly where Bret's center will move across the Lesser 
Antilles island chain.
 
 
KEY MESSAGES:
 
1. Bret is forecast to approach the Lesser Antilles through
Thursday morning and then move across those islands Thursday
afternoon and Thursday night as a strong tropical storm, bringing a 
risk of flooding from heavy rainfall, strong winds, and dangerous 
waves along the coast.
 
2. Given the uncertainty in the track and intensity forecasts, it
is too early to specify the location and magnitude of where Bret's
associated hazards could occur.  A Tropical Storm Watch is in 
effect for Barbados, Dominica, Martinique, and St. Lucia, and
additional watches and warnings are likely for these and other
islands in the Lesser Antilles today.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/0900Z 12.8N  51.4W   50 KT  60 MPH
 12H  21/1800Z 13.1N  53.3W   55 KT  65 MPH
 24H  22/0600Z 13.5N  55.7W   55 KT  65 MPH
 36H  22/1800Z 13.8N  58.5W   55 KT  65 MPH
 48H  23/0600Z 14.2N  61.8W   50 KT  60 MPH
 60H  23/1800Z 14.5N  65.3W   45 KT  50 MPH
 72H  24/0600Z 14.8N  69.0W   40 KT  45 MPH
 96H  25/0600Z 15.0N  76.0W   30 KT  35 MPH
120H  26/0600Z...DISSIPATED
 
$$
Forecaster Pasch
 
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