Official Discussion issued by the National Hurricane Center

Vicky (AL212020) DATA RELEASED: 9/15/2020 9:00:00 AM UTC

Copy of official data

Tropical Storm Vicky Discussion Number   5
NWS National Hurricane Center Miami FL       AL212020
500 AM AST Tue Sep 15 2020

Vicky remains sheared this morning with strong upper-level winds 
causing any deep convection to be located northeast of the center.  
The low-level circulation has also become distorted as well, with 
new bursts of convection causing the mean circulation to re-form to 
the north.  The initial wind speed is kept 45 kt since the system 
isn't appreciably different than the last cycle.  Models all weaken 
the storm during the next couple of days due to rather potent 
westerly shear (with 200-mb westerly winds as high as 70 kt 
forecast across Vicky's circulation).  These extremely harsh 
conditions should make the intensity prediction rather simple, and 
Vicky is likely to decay into a remnant low within a day or two 
and open up into a trough in a few days.

The re-formation of the center leads to an uncertain motion 
estimate of 325/8 kt.  The storm should turn west-northwestward 
later today and westward on Wednesday as it becomes steered by the 
low-level subtropical ridge.  Little change was made to the 
previous forecast, except for a small northward adjustment in the 
first day or so of the prediction due to the initial position.


FORECAST POSITIONS AND MAX WINDS

INIT  15/0900Z 20.3N  30.1W   45 KT  50 MPH
12H  15/1800Z 21.0N  31.2W   40 KT  45 MPH
24H  16/0600Z 21.7N  33.1W   35 KT  40 MPH
36H  16/1800Z 22.2N  35.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
48H  17/0600Z 22.5N  37.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
60H  17/1800Z 22.5N  38.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  18/0600Z 22.5N  40.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  19/0600Z...DISSIPATED

$$
Forecaster Blake