Tropical Storm Dexter Forecast Discussion Number 5

By | August 5, 2025

Issued at 1100 PM AST Mon Aug 04 2025

146 
WTNT44 KNHC 050239
TCDAT4
 
Tropical Storm Dexter Discussion Number   5
NWS National Hurricane Center Miami FL       AL042025
1100 PM AST Mon Aug 04 2025

Dexter continues to be disrupted by strong westerly vertical wind 
shear, with its associated deep convection being displaced to the 
east of the low-level center.  The storm's cloud pattern is very 
ragged-looking at this time and lacks convective banding features.
Satellite-based intensity estimates using subjective and objective 
methods range from 30 kt to 47 kt.  Blending these values, the 
advisory intensity estimate remains 40 kt, though a recent 
scatterometer pass suggests this might be generous.

Although there is some uncertainty in the center location using 
infrared imagery, it appears that the forward speed has slowed 
somewhat and the current motion estimate is around 050/11 kt.  
Dexter is near the southern edge of a belt of mid-level westerlies. 
The track guidance is in general agreement on a northeastward to 
east-northeastward motion for the next several days.  However, it 
is possible that the system could become completely decoupled and 
move more slowly in the low-level flow.  The official forecast 
assumes that the cyclone will retain enough vertical coherency to 
be steered at least partially by the mid-level flow.  The NHC track 
forecast is fairly close to the latest corrected consensus, HCCA, 
guidance.

There is no sign that the strong shear in Dexter's environment will 
abate.  In fact, the SHIPS model indicates that the vertical wind 
shear will increase even more over the next few days.  Therefore, 
it is not likely that the system will be able to strengthen as a 
true tropical cyclone.  The official forecast allows for slight 
intensification due to baroclinic processes.  Simulated infrared 
imagery and the FSU phase space predictions from the global 
models suggest that Dexter will likely make the transition 
into an extratropical cyclone in 2-3 days.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  05/0300Z 36.8N  65.6W   40 KT  45 MPH
 12H  05/1200Z 37.8N  64.1W   40 KT  45 MPH
 24H  06/0000Z 38.9N  62.1W   40 KT  45 MPH
 36H  06/1200Z 39.6N  59.7W   40 KT  45 MPH
 48H  07/0000Z 40.2N  56.7W   40 KT  45 MPH
 60H  07/1200Z 41.2N  52.9W   45 KT  50 MPH...POST-TROP/EXTRATROP
 72H  08/0000Z 42.8N  48.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
 96H  09/0000Z 46.0N  39.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  10/0000Z 49.0N  29.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
 
$$
Forecaster Pasch

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