Tropical Storm Vicky Discussion Number 2
NWS National Hurricane Center Miami FL AL212020
200 PM CVT Mon Sep 14 2020
A METOP A/B ASCAT scatterometer pass over the cyclone showed a large
swath of winds in the northeast quadrant on the order of 35 to 39
kt. Deep convection in that region of the cyclone continues to
increase as well as near the center of circulation. Accordingly,
the initial intensity is raised to 40 kt, making this the twentieth
named storm of the season. This should be a short-lived tropical
cyclone, however, as increasing southwesterly shear is expected to
quickly weaken Vicky to a depression in a couple days, and the
system is expected to degenerate to a remnant low Thursday. This
scenario is based on a combination of the global models and the
ECMWF and FV3 SHIPS statistical-dynamical intensity models.
The initial motion estimate is an uncertain 325/05 kt. The cyclone
is forecast to move northwestward with some increase in forward
speed during the next 24 hours within the low to mid-level steering
flow produced by the eastern end of the African monsoon trough. By
Tuesday night, Vicky should turn west-northwestward to westward
along the southern periphery of a subtropical ridge over the
eastern Atlantic. The official track forecast is close to the
various consensus aids and is just to the north of the previous
advisory beyond 36 hours.