NATIONAL HURRICANE CENTER and
CENTRAL PACIFIC HURRICANE CENTER

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Tropical Storm Polo Discussion Number   5
NWS National Hurricane Center Miami FL       EP212020
100 PM PST Wed Nov 18 2020
 
While the cloud pattern was fairly well organized this morning, Polo 
provided a little surprise when the center popped out of the central 
dense overcast.  The system has since developed deep convection near 
the center, so perhaps this was a temporary fluctuation but reflects 
marginal environmental conditions.  The initial wind speed is kept 
at 40 kt as a blend of the satellite data, and unfortunately 
scatterometer data missed again for a more certain estimate.  Polo 
probably will peak in intensity during the next 12 hours or so 
before a combination of higher shear and dry/stable air causes the 
storm to weaken and eventually become a remnant low on Friday.  No 
significant changes were made to the intensity forecast, and there 
were no meaningful model outliers from the NHC prediction.
 
At least the exposed center allowed for a more precise initial 
motion estimate, though it ended up about the same as before 285/10. 
 Model guidance is tightly clustered on the storm turning westward 
tomorrow while it remains to the south of a low- to mid-level ridge. 
 The small cyclone will likely decay into a trough of low pressure 
by the weekend.  Only cosmetic changes were made to the last 
forecast, which continues to lie near or just south of the model 
consensus.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  18/2100Z 16.5N 117.2W   40 KT  45 MPH
 12H  19/0600Z 16.8N 118.9W   40 KT  45 MPH
 24H  19/1800Z 17.0N 120.9W   35 KT  40 MPH
 36H  20/0600Z 17.1N 123.0W   30 KT  35 MPH
 48H  20/1800Z 17.1N 125.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  21/0600Z...DISSIPATED
 
$$
Forecaster Blake
 
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