Hurricane Paulette Discussion Number  28
NWS National Hurricane Center Miami FL       AL172020
500 PM AST Sun Sep 13 2020

Paulette has recovered from the dry air intrusion that was eroding 
the eastern eyewall this morning. A ring of deep convection with 
cloud tops ranging from about -50 to -65 C now completely surrounds 
a partially cleared eye. An Air Force Hurricane Hunter aircraft 
investigating the hurricane earlier this afternoon measured peak 
flight-level winds of 84 kt, which reduces to about 67 kt at the 
surface. However, since that time there has been steady improvement 
in the satellite presentation, and the latest Dvorak satellite 
T-numbers from TAFB and SAB are now at 4.5, supporting increasing 
the initial intensity to 75 kt for this advisory. 

Paulette is expected to remain in a low-shear environment over warm 
SSTs for the next 24-36 h, so gradual strengthening is likely during 
that time. Around 48 h from now, vertical wind shear is forecast to 
rapidly increase ahead of an approaching mid- upper level trough. 
This should cause the cyclone to begin weakening. By 72 h, Paulette 
is expected to be over waters less that 26 degrees C and should 
remain over cooler waters for the remainder of the forecast period. 
Around that same time, global models are indicating that the cyclone 
will begin to interact with a frontal boundary associated with the 
aforementioned trough. This should induce a gradual transition of 
Paulette to an extratropical cyclone, and that transition should be 
completed by 120 h, if not sooner. The latest NHC intensity forecast 
is little changed from the previous one and shows Paulette 
continuing to strengthen as it passes near or over Bermuda early 
Monday. The forecast also shows Paulette becoming a major hurricane 
by Monday night, after the cyclone has moved away from Bermuda. This 
intensity forecast is in good agreement with the HFIP corrected 
consensus, HCCA.

Paulette is moving northwestward at 11 kt, to the southwest of a 
mid-level ridge. There is no change to the forecast track reasoning. 
This northwest motion should continue until just after the cyclone 
passes Bermuda Monday morning. Later on Monday, the hurricane should 
turn north, then northeastward, as it rounds the periphery of the 
ridge. After turning northeastward, the cyclone is expected to 
accelerate as it gets picked up in the mid-latitude flow ahead of 
the approaching trough. Later on in the forecast period a slower 
eastward motion is indicated once the trough bypasses the cyclone. 
The latest NHC forecast was nudged only slightly to the left of the 
previous one, and is in agreement with tightly clustered global and 
regional track guidance. Tropical storm conditions should reach 
Bermuda in the next couple of hours, with hurricane force winds 
arriving there overnight.

Key Messages:

1. Paulette is expected to approach Bermuda as a hurricane today
and will be near the island tonight and Monday.  A prolonged
period of strong winds, storm surge, and heavy rainfall is expected
on Bermuda beginning this evening, and a hurricane warning is in
effect for the island.  Preparations to protect life and property
should be rushed to completion.

2. Swells produced by Paulette are affecting portions of the
Leeward Islands, the Greater Antilles, the Bahamas, Bermuda, and
the east coast of the United States. These swells could cause
life-threatening surf and rip current conditions.


FORECAST POSITIONS AND MAX WINDS

INIT  13/2100Z 30.6N  63.1W   75 KT  85 MPH
12H  14/0600Z 31.8N  64.5W   85 KT 100 MPH
24H  14/1800Z 33.9N  64.8W   95 KT 110 MPH
36H  15/0600Z 36.1N  62.4W  100 KT 115 MPH
48H  15/1800Z 38.1N  57.8W  100 KT 115 MPH
60H  16/0600Z 40.3N  52.6W   95 KT 110 MPH
72H  16/1800Z 42.4N  47.4W   80 KT  90 MPH
96H  17/1800Z 45.5N  38.7W   60 KT  70 MPH
120H  18/1800Z 44.4N  34.1W   45 KT  50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Latto