Official Discussion issued by the National Hurricane Center

Paulette (AL172020) DATA RELEASED: 9/10/2020 9:00:00 PM UTC

Copy of official data

Tropical Storm Paulette Discussion Number  16
NWS National Hurricane Center Miami FL       AL172020
500 PM AST Thu Sep 10 2020

Continuous bursts of deep convection have been ongoing to the north 
and northeast of Paulette's center of circulation, with the cyclone 
being affected by nearly 40 kt of deep-layer southwesterly shear.  
The highest intensity estimates are Dvorak classifications of 
T3.0/45 kt from TAFB and SAB, and that value remains the initial 
intensity.  The shear should reach its peak magnitude this evening, 
which is likely to cause Paulette to weaken slightly during the 
next 24 hours.  However, gradual re-strengthening is forecast to 
begin in about 36 hours, and the rate of intensification is expected 
to increase in 2 to 3 days when the shear could fall to 10 kt or 
less, along with a more unstable atmosphere and warmer sea surface 
temperatures.  Paulette is now forecast to become a hurricane by day 
3 and continue to intensify through the end of the forecast period.  
As was advertised in the previous forecast package, the new NHC 
forecast intensities have been bumped up on days 3 through 5 and 
now lie near or just below the IVCN intensity consensus and the 
HCCA corrected consensus aid.

Paulette's heading over the past 6-12 hours has been toward the 
west-northwest, or 300/8 kt.  The cyclone's trajectory is expected 
to oscillate between northwest and west-northwest for the next 4 
days, being dictated by the strength of the subtropical ridge to 
the north and the depth of the steering flow depending on 
Paulette's intensity.  The updated NHC track forecast during this 
period has been nudged a bit to the north, mostly to account for an 
adjustment of the initial position.  The model guidance all agree 
that Paulette should turn northward around the western side of a 
central Atlantic high pressure area by day 5, with the expected 
hurricane likely to make a tight recurvature near Bermuda.  There 
remains some uncertainty on exactly where that turn will occur, but 
for now the NHC forecast lies between the tighter-turning ECMWF and 
HCCA models and the more gradually-turning GFS and HWRF models.

Key Messages:

1.  Paulette is expected to approach Bermuda as a hurricane this 
weekend and make its closest approach to the island on Monday and 
Tuesday.  While the exact details of Paulette's track and intensity 
near the island are not yet known, the risk of strong winds, storm 
surge, and heavy rainfall on Bermuda continues to increase.

2.  Swells produced by Paulette are expected to affect portions of 
the Leeward Islands, 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  10/2100Z 22.1N  50.1W   45 KT  50 MPH
12H  11/0600Z 22.5N  51.5W   40 KT  45 MPH
24H  11/1800Z 23.6N  53.4W   40 KT  45 MPH
36H  12/0600Z 25.0N  55.1W   45 KT  50 MPH
48H  12/1800Z 26.6N  56.8W   45 KT  50 MPH
60H  13/0600Z 28.0N  58.9W   55 KT  65 MPH
72H  13/1800Z 29.2N  61.4W   65 KT  75 MPH
96H  14/1800Z 31.5N  65.5W   75 KT  85 MPH
120H  15/1800Z 34.5N  64.0W   80 KT  90 MPH

Forecaster Berg