Official Discussion issued by the National Hurricane Center

Epsilon (AL272020) DATA RELEASED: 10/20/2020 9:00:00 PM UTC

Copy of official data

Tropical Storm Epsilon Discussion Number   7
NWS National Hurricane Center Miami FL       AL272020
500 PM AST Tue Oct 20 2020

EpsilonĘs structure has greatly improved this afternoon. Deep 
convection is wrapped more tightly around the center, and a small 
central dense overcast is evident in recent satellite imagery. 
Overall, the cyclone appears better organized and more tropical in 
nature as it fends off weak to moderate deep-layer shear and some 
dry mid-level air in its surrounding environment. There are even 
some hints of an eye-like feature trying to develop in recent 
visible and microwave imagery. A 14Z ASCAT-B overpass showed several 
45-50 kt wind barbs in the northern semicircle of Epsilon, and its 
organization has improved since then. A T3.5 Dvorak classification 
from SAB supports raising the initial intensity to 55 kt with this 
advisory. Epsilon is a large cyclone with tropical-storm-force winds 
extending outward as far as 300 n mi in its northern semicircle.

The cyclone has accelerated northwestward today, and its estimated 
motion is a somewhat uncertain 320/12 kt. Epsilon should continue to 
move northwestward or west-northwestward for the next several days 
as it is steered by a mid-level ridge to its north and east. The 
tightly clustered guidance envelope has shifted slightly westward 
and is faster with the storm motion through about 72 h, and these 
trends are reflected in the official NHC track forecast. Epsilon is 
now forecast to make its closest approach to Bermuda late Thursday 
night before recurving ahead of an upper-level trough that should 
move over the western Atlantic this weekend. By day 5, Epsilon could 
be near the beginning of its extratropical transition as it races 
northeastward across the central Atlantic.

Epsilon has strengthened today despite some negative environmental 
factors including weak to moderate deep-layer shear and dry air 
noted in water vapor imagery along the southwestern periphery of the 
storm. Given recent satellite trends and little expected change in 
the environmental conditions during the next day or so, additional 
strengthening appears likely. The official NHC track forecast lies 
well above the guidance consensus in the near term and most closely 
follows the SHIPS output, which brings Epsilon to hurricane strength 
overnight. As the cyclone gains latitude and moves over waters with 
lower oceanic heat content beyond 48 h, the intensity is expected to 
level off, and the NHC forecast better aligns with the ICON and HCCA 
aids through the rest of the forecast period.


Key Message:

1. Epsilon is forecast to be at or near hurricane strength when it
makes its closest approach to Bermuda late Thursday or early 
Friday.  While it is too soon to determine the exact details of 
Epsilon's track and intensity near the island, tropical storm 
conditions are possible on Bermuda beginning Thursday with dangerous 
surf conditions also likely. 


FORECAST POSITIONS AND MAX WINDS

INIT  20/2100Z 27.9N  55.8W   55 KT  65 MPH
12H  21/0600Z 28.8N  57.8W   65 KT  75 MPH
24H  21/1800Z 29.3N  59.6W   70 KT  80 MPH
36H  22/0600Z 30.3N  60.5W   75 KT  85 MPH
48H  22/1800Z 31.6N  61.2W   75 KT  85 MPH
60H  23/0600Z 33.0N  61.6W   75 KT  85 MPH
72H  23/1800Z 34.0N  61.8W   75 KT  85 MPH
96H  24/1800Z 36.7N  60.7W   75 KT  85 MPH
120H  25/1800Z 42.0N  51.0W   70 KT  80 MPH

$$
Forecaster Reinhart/Brown