Official Discussion issued by the National Hurricane Center

Paulette (AL172020) DATA RELEASED: 9/15/2020 9:00:00 PM UTC

Copy of official data

Hurricane Paulette Discussion Number  36
NWS National Hurricane Center Miami FL       AL172020
500 PM AST Tue Sep 15 2020

Another fortuitous AMSR2 microwave pass over the cyclone showed the
outer concentric ring open over the south semicircle and a more
noticeable vertical tilt.  Furthermore, the cloud tops associated
with the deep convection in the north quadrant have warmed during
the past several hours.  Consequently, the initial intensity is
lowered to 85 kt and is in best agreement with the subjective and
objective satellite intensity estimates.

Paulette continues to lose its tropical characteristics as it 
mingles with the rapidly approaching baroclinic zone from the 
northwest.  In fact, earlier successive METOP A and B scatterometer 
passes on Paulette revealed that the northwest quadrant 34-kt wind 
radii had nearly doubled in size due to the aforementioned invading 
frontal zone moving out of the Canadian Maritimes.  The sea surface 
temperatures quickly decrease to less than 20C within 24 hours as 
Paulette accelerates east-northeastward.  As a result, the cyclone 
should weaken rather quickly and complete its extratropical 
transition on Thursday, as indicated in the global models and the 
statistical-dynamical guidance.

Paulette is moving east-northeastward, or 060/26 kt, and this motion 
should continue with a further increase in forward speed through 
Thursday.  Toward the end of the week, the cyclone will likely turn 
south-southeastward to southward as it moves within the western 
peripheral flow of a mid- to upper tropospheric cut off low to the 
east of the cyclone.  The NHC track forecast is basically an update 
of the previous advisory and is based on the various consensus 

The initial wind radii and subsequent forecast wind radii were 
adjusted based on METOP A/B ASCAT 1110 UTC and 1424 UTC 
scatterometer passes.


INIT  15/2100Z 39.5N  55.0W   85 KT 100 MPH
12H  16/0600Z 41.4N  50.1W   80 KT  90 MPH
24H  16/1800Z 44.0N  42.9W   70 KT  80 MPH
36H  17/0600Z 45.8N  36.8W   55 KT  65 MPH...POST-TROP/EXTRATROP
48H  17/1800Z 45.8N  33.7W   50 KT  60 MPH...POST-TROP/EXTRATROP
60H  18/0600Z 43.9N  32.8W   45 KT  50 MPH...POST-TROP/EXTRATROP
72H  18/1800Z 41.2N  32.8W   40 KT  45 MPH...POST-TROP/EXTRATROP
96H  19/1800Z 38.0N  32.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  20/1800Z 34.5N  32.3W   35 KT  40 MPH...POST-TROP/EXTRATROP

Forecaster Roberts