Official Discussion issued by the National Hurricane Center

Paulette (AL172020) DATA RELEASED: 9/14/2020 9:00:00 PM UTC

Copy of official data

Hurricane Paulette Discussion Number  32
NWS National Hurricane Center Miami FL       AL172020
500 PM AST Mon Sep 14 2020

Overall, Paulette's satellite presentation has improved during the 
past several hours.  In fact, a 1743 UTC AMSR2 microwave pass 
showed a developing concentric eyewall cloud pattern with a fully 
enclosed eyewall and a larger outer convective ring that was nearly 
closed off.  A blend of the UW-CIMSS objective T-number of 94 kt and 
the Dvorak satellite intensity estimates from TAFB and SAB yields 
an initial intensity of 90 kt for this advisory.

Additional strengthening is expected as Paulette moves away from
Bermuda and accelerates northeastward over the North Atlantic.
Paulette should be at or near major hurricane strength within the
next 12-24 hours.  On Wednesday, weakening is expected to begin
as the cyclone traverses a sharp gradient of decreasing (less
than 23C) oceanic temperatures.  Around the same time, the 
deterministic models are indicating that the cyclone will begin to 
interact with a baroclinic boundary associated with major shortwave 
trough.  Paulette should begin to lose its tropical characteristics 
at that time and complete an extratropical cyclone transition in 3 
days.  The ECMWF and FV3 SHIPS intensity models show the transition 
completed in 48 hours, which is also a possibility.

The initial motion is estimated to be north-northeastward, or 
030/13 kt.  Paulette will begin accelerating northeastward by 
Tuesday morning, and then turn east-northeastward with a further 
increase in forward speed by Tuesday night.  A slower southeastward 
motion is forecast on Friday in response to a larger mid- to upper 
tropospheric cut-off low approaching the eastern  Atlantic.  The NHC 
forecast is basically an update of the previous  advisory and is 
very close to the HFIP Corrected Consensus Approach model and lies 
down the middle of the tightly clustered various interpolated 
deterministic aids.

The initial wind radii and subsequent forecast wind radii were
adjusted based on METOP A/B ASCAT 1232 UTC scatterometer passes.


INIT  14/2100Z 34.5N  63.8W   90 KT 105 MPH
12H  15/0600Z 36.1N  61.9W  100 KT 115 MPH
24H  15/1800Z 38.4N  57.2W  110 KT 125 MPH
36H  16/0600Z 40.8N  51.3W  110 KT 125 MPH
48H  16/1800Z 43.3N  44.9W   90 KT 105 MPH
60H  17/0600Z 45.4N  39.4W   65 KT  75 MPH
72H  17/1800Z 46.6N  35.8W   50 KT  60 MPH...POST-TROP/EXTRATROP
96H  18/1800Z 44.3N  32.6W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  19/1800Z 39.1N  31.3W   35 KT  40 MPH...POST-TROP/EXTRATROP

Forecaster Roberts