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Tropical Storm Vicky Discussion Number   8
NWS National Hurricane Center Miami FL       AL212020
1100 PM AST Tue Sep 15 2020

Vicky provided a surprise this evening, with scatterometer data 
showing a solid 45-kt in the northwestern quadrant of the storm.  
You would never guess it from the satellite images, which show a 
very sheared system that would at best support an 30-35 kt 
intensity, as indicated by the latest Dvorak estimates.  The initial 
wind speed is set to 45 kt, higher than the last time but not really 
a true strengthening since conventional satellite data was a bit 
deceptive earlier.  Despite Vicky holding its own, models are still 
showing the strong shear persisting, which should eventually cause 
weakening.  The cyclone is likely to last longer than previously 
anticipated though with some upper-level divergence counteracting 
the effects of the shear, but Vicky is forecast gradually lose 
strength and decay in a remnant low in a couple of days, similar to 
the consensus guidance.  
 
The storm continues to more west-northwestward, a little to the 
left of previous, at 290/10.  Vicky should gradually turn westward 
tomorrow and west-southwestward later this week as it becomes a 
shallower cyclone.  The new forecast is quite similar to the 
previous one, leaning on the northern side of the well-clustered 
guidance envelope since Vicky is persisting as a deeper cyclone for 
the moment. The only small change is to add a 72-hour forecast 
point as the remnants could linger for a while longer.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/0300Z 21.6N  33.1W   45 KT  50 MPH
 12H  16/1200Z 22.0N  34.5W   40 KT  45 MPH
 24H  17/0000Z 22.3N  36.3W   35 KT  40 MPH
 36H  17/1200Z 22.4N  38.0W   30 KT  35 MPH
 48H  18/0000Z 22.3N  39.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 60H  18/1200Z 22.0N  41.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  19/0000Z 21.5N  43.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  20/0000Z...DISSIPATED
 
$$
Forecaster Blake
 
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