Tropical Storm Polo Discussion Number 4
NWS National Hurricane Center Miami FL EP212020
700 AM PST Wed Nov 18 2020
Satellite images indicate that the depression has strengthened into
a tropical storm. The small central dense overcast has grown
during the past several hours and a few banding features have
formed. Dvorak estimates range from 30 to 45 kt, and the initial
wind speed is set to 40 kt, which matches the latest CIMSS
satellite consensus estimate. Polo could strengthen a little more
today, but an increase in shear and dry-air entrainment should
start the weakening process on Thursday, with the system expected
to become a non-convective remnant low on Friday. The new NHC
forecast is a little below the model consensus, close to the
previous NHC forecast, leaning toward the idea that the small
tropical cyclone will probably weaken faster than the bulk of the
guidance anticipates.
The initial motion continues to be west-northwestward at 10 kt.
There has been no change to the forecast philosophy, with Polo
forecast to remain on the southern side of a mid-level ridge
throughout the period. The storm should turn more westward on
Thursday as the system weakens and becomes more shallow. The new
forecast is south of the latest model consensus, nudged slightly
north of the previous NHC forecast.
