Official Discussion issued by the National Hurricane Center

Paulette (AL172020) DATA RELEASED: 9/11/2020 3:00:00 PM UTC

Copy of official data

Tropical Storm Paulette Discussion Number  19
NWS National Hurricane Center Miami FL       AL172020
1100 AM AST Fri Sep 11 2020

Despite what is being analyzed as roughly 40 kt of deep-layer 
southwesterly shear, Paulette's center is embedded beneath the 
cirrus canopy of a strong convective burst to the north.  Recent 
microwave images do confirm, however, that the center remains 
displaced from the convection.  We have not yet received new 
scatterometer data over Paulette, and since the structure has not 
degraded from overnight, the initial intensity remains 55 kt.  This 
is in best agreement with the Dvorak estimate from TAFB.

Paulette appears to have turned toward the northwest (305/9 kt) 
based on center fixes over the past 12 hours.  A weakness in the 
subtropical ridge is beginning to develop to the north of Paulette, 
which should allow the cyclone to maintain a motion toward the 
northwest or west-northwest during the next 3 days.  After that 
time, a longwave trough forecast to move across the northeastern 
United States is expected to erode the ridge eastward, causing 
Paulette to recurve sharply toward the north and northeast in the 
vicinity of Bermuda on days 4 and 5.  Except for some minor speed 
differences, the track models agree on this general trajectory and 
have less east-to-west spread during the recurvature phase than 
they did yesterday.  The GFS, ECMWF, HCCA, and Florida State 
Superensemble aids all lie along the western side of the guidance 
envelope at the time of recurvature, and as a result the new NHC 
track has been nudged a little west of the previous prediction 
during that period in deference to those normally reliable models.

The shear affecting Paulette is forecast to abate over the next 48 
hours while the storm also moves over warmer ocean waters and into 
a more unstable environment.  Given the cyclone's hardiness in the 
face of the ongoing shear, Paulette is unlikely to have problems 
responding to the improving environment.  Paulette is now forecast 
to become a hurricane in 36 hours, which is supported by the latest 
dynamical hurricane models, the superensemble aids, and the IVCN 
intensity consensus.  Continued strengthening is anticipated after 
36 hours, with Paulette likely to reach a peak intensity in 4-5 

Key Messages:

1.  Paulette is expected to approach Bermuda as a hurricane this
weekend and make its closest approach to the island on Monday.  
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 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  11/1500Z 23.6N  52.2W   55 KT  65 MPH
12H  12/0000Z 24.6N  53.7W   55 KT  65 MPH
24H  12/1200Z 26.1N  55.5W   60 KT  70 MPH
36H  13/0000Z 27.6N  57.5W   65 KT  75 MPH
48H  13/1200Z 28.9N  59.9W   75 KT  85 MPH
60H  14/0000Z 30.2N  62.5W   80 KT  90 MPH
72H  14/1200Z 31.6N  64.3W   85 KT 100 MPH
96H  15/1200Z 34.5N  63.5W   90 KT 105 MPH
120H  16/1200Z 37.0N  58.0W   90 KT 105 MPH

Forecaster Berg