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Post-Tropical Cyclone Earl Forecast Discussion



000
WTNT41 KNHC 102040
TCDAT1

Post-Tropical Cyclone Earl Discussion Number  32
NWS National Hurricane Center Miami FL       AL062022
500 PM AST Sat Sep 10 2022

Satellite imagery shows that Earl has completed extratropical 
transition, with well-developed frontal features and a central core 
that is void of deep convection.  While recent scatterometer 
overpasses did not sample the strongest winds, it showed that Earl 
remains both large and powerful as an extratropical low.  So, the 
initial intensity is set at 75 kt at this time.  The global models 
are in good agreement that the system should gradually weaken 
during the forecast period, with the maximum winds dropping below 
hurricane force between 12-24 h.  The intensity forecast follows 
the trend of the intensity guidance and has some minor adjustments 
from the previous forecast.

Earl has slowed its forward speed considerably since the last 
advisory, with the motion now 025/9 kt.  A slow movement toward the 
northeast is expected during the next 36 h as the system merges 
with a mid-latitude trough.  After that, the post-tropical cyclone 
is expected to move eastward through 96 h, followed by an 
east-northeastward motion.  The track guidance has shifted 
southward between 36-72 h, and the new forecast track is adjusted 
southward during that time as well.  The forecast slow motion, 
along with Earl's large wind field, will cause strong winds over 
the Avalon Peninsula of Newfoundland from this afternoon through 
Sunday. For additional information on impacts in Newfoundland, 
please monitor forecasts and warnings from Environment Canada.

The is the last advisory issued by the National Hurricane Center on 
Earl.  Additional information on this system can be found in High 
Seas Forecasts issued by the National Weather Service, under AWIPS
header NFDHSFAT1, WMO header FZNT01 KWBC, and online at 
ocean.weather.gov/shtml/NFDHSFAT1.php


KEY MESSAGES:

1. Strong winds are expected over the Avalon Peninsula of
Newfoundland this afternoon through Sunday.

2. Large swells generated by Earl will affect Bermuda, portions
of the U.S. East Coast, and Nova Scotia and Newfoundland during the
next several days.  These swells are likely to cause
life-threatening surf and rip current conditions.  Please consult
products from your local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT  10/2100Z 43.6N  52.6W   75 KT  85 MPH...POST-TROP/EXTRATROP
 12H  11/0600Z 44.3N  52.0W   65 KT  75 MPH...POST-TROP/EXTRATROP
 24H  11/1800Z 44.8N  51.4W   55 KT  65 MPH...POST-TROP/EXTRATROP
 36H  12/0600Z 45.0N  50.8W   45 KT  50 MPH...POST-TROP/EXTRATROP
 48H  12/1800Z 44.9N  49.8W   40 KT  45 MPH...POST-TROP/EXTRATROP
 60H  13/0600Z 44.7N  47.3W   40 KT  45 MPH...POST-TROP/EXTRATROP
 72H  13/1800Z 44.7N  44.4W   40 KT  45 MPH...POST-TROP/EXTRATROP
 96H  14/1800Z 45.5N  40.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  15/1800Z 47.5N  36.5W   35 KT  40 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven



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