Official Discussion issued by the National Hurricane Center

(AL202020) DATA RELEASED: 9/23/2020 9:00:00 AM UTC

Copy of official data

Post-Tropical Cyclone Teddy Discussion Number  44
NWS National Hurricane Center Miami FL       AL202020
500 AM AST Wed Sep 23 2020

Teddy's deep convection has been diminishing, but based on buoy
observations the cyclone still has a strong circulation with a 
central pressure in the 950's.  Assuming a gradual spindown of the 
system since the earlier aircraft observations, the estimated 
maximum winds have dropped to just below hurricane strength.  The 
system is expected to traverse Nova Scotia today as a strong 
extratropical cyclone, and move near Newfoundland by tonight.  After 
passing east of Labrador on Thursday, the global models show Teddy 
merging with another large extratropical low over the north 
Atlantic.

The estimated initial motion is north-northeastward or 025/20 kt.  
Teddy is embedded within a deep-layer trough that is located in the 
vicinity of Atlantic Canada.  The post-tropical cyclone should move 
north-northeastward on the eastern side of the trough for the next 
36-48 hours before it merges with the other low.  The official 
track forecast is very similar to the previous one and also closely 
follows the corrected multi-model consensus, HCCA.

Even after Teddy passes Nova Scotia and Newfoundland, large swells 
will linger over much of the southwestern Atlantic basin for the 
next few days.

Key Messages:

1. Teddy is expected remain a powerful post-tropical cyclone 
while it moves near or over portions of Atlantic Canada through 
tonight. The most significant hazard expected from Teddy is large 
destructive waves forecast along the southern coast of Nova Scotia 
today.

2. Very large swells produced by Teddy are expected to affect
portions of Bermuda, the Leeward Islands, the Greater Antilles, the
Bahamas, the east coast of the United States, and Atlantic Canada
during the next few days. These swells are expected to cause
life-threatening surf and rip current conditions.

3. Tropical Storm Watches and Warnings are in effect for portions
of Nova Scotia, Newfoundland, Prince Edward Island and the Magdalen
Islands, and heavy rainfall across Atlantic Canada is expected
through Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  23/0900Z 44.5N  62.7W   60 KT  70 MPH...POST-TROP/EXTRATROP
12H  23/1800Z 47.5N  60.6W   55 KT  65 MPH...POST-TROP/EXTRATROP
24H  24/0600Z 52.3N  56.7W   45 KT  50 MPH...INLAND
36H  24/1800Z 57.0N  53.5W   40 KT  45 MPH...POST-TROP/EXTRATROP
48H  25/0600Z...POST-TROP/EXTRATROP

$$
Forecaster Pasch