Official Discussion issued by the National Hurricane Center

Paulette (AL172020) DATA RELEASED: 9/11/2020 9:00:00 PM UTC

Copy of official data

Tropical Storm Paulette Discussion Number  20
NWS National Hurricane Center Miami FL       AL172020
500 PM AST Fri Sep 11 2020

Paulette inconveniently fell in a gap between all three ASCAT 
passes this morning, so we haven't gotten any better handle on the 
cyclone's intensity since last evening's pass.  However, Dvorak 
classifications have not budged, so maintaining the initial 
intensity of 55 kt seems sound.  In addition, although an AMSR 
microwave pass from around 17 UTC still showed the system being 
sheared, it also revealed a ragged mid-level eye feature.  Since 
the shear is expected to abate to less than 10 kt by 48 hours, 
Paulette is likely to intensify, possibly significantly so, and it 
is now forecast to become a hurricane on Saturday.  The 
intensification trend is expected to continue through day 4, and 
Paulette has the potential to be a dangerous hurricane when it 
makes its closest approach to Bermuda on Monday.  Paulette's 
forecast peak intensity (on day 4) has been nudged up slightly, 
lying near the SHIPS and HCCA guidance, but still a little below 
the latest HWRF simulation.

Paulette has picked up some speed and is now moving toward the 
northwest (310 degrees) at 11 kt.  The track forecast reasoning 
has not changed since this morning.  Paulette should maintain a 
motion toward the northwest or west-northwest during the next 2 to 
3 days to the south of a weakening subtropical ridge.  By day 3, a 
longwave trough is forecast to move across the northeastern
United States, eroding the ridge eastward, and causing Paulette to 
recurve sharply toward the north and northeast in the vicinity of 
Bermuda on Monday.  After that time, Paulette is forecast to become 
embedded in the mid-latitude flow and accelerate northeastward 
toward the north Atlantic.  The spread in the track guidance has 
continued to tighten up, which increases the confidence in the 
official track forecast.  The updated forecast has been shifted 
slightly westward around the time that Paulette will be near 
Bermuda, and it is embedded among the usually-reliable GFS, ECMWF, 
and HCCA model solutions.

Key Messages:

1.  Paulette is expected to approach Bermuda as a hurricane during 
the next couple of days and make its closest approach to the island 
on Monday.  A prolonged period of strong winds, storm surge, and 
heavy rainfall on Bermuda beginning Sunday night is becoming more 
likely, and a hurricane watch could be required for the island 
tonight or early Saturday.  

2.  Swells produced by Paulette are affecting portions of the
Leeward Islands and will continue to spread westward to the Greater
Antilles, the Bahamas, Bermuda, and the southeastern United States
into the weekend.  These swells could cause life-threatening surf
and rip current conditions.


INIT  11/2100Z 24.6N  53.7W   55 KT  65 MPH
12H  12/0600Z 25.9N  55.3W   60 KT  70 MPH
24H  12/1800Z 27.5N  57.5W   65 KT  75 MPH
36H  13/0600Z 28.7N  59.8W   70 KT  80 MPH
48H  13/1800Z 29.8N  62.3W   80 KT  90 MPH
60H  14/0600Z 31.1N  64.5W   85 KT 100 MPH
72H  14/1800Z 32.6N  65.3W   90 KT 105 MPH
96H  15/1800Z 36.0N  62.0W   95 KT 110 MPH
120H  16/1800Z 39.0N  56.0W   85 KT 100 MPH

Forecaster Berg