000
WTNT45 KNHC 201437
TCDAT5
 
Post-Tropical Cyclone Ernesto Discussion Number  36
NWS National Hurricane Center Miami FL       AL052024
300 PM GMT Tue Aug 20 2024
 
Strong southwesterly vertical wind shear and cold sea-surface 
temperatures have caused Ernesto to lose tropical characteristics 
this morning. The cyclone lacks organized convection, and the 
low-level center is becoming exposed as dry air wraps into the 
circulation. Also, GFS phase diagrams indicate Ernesto no longer has 
a warm-core structure. Thus, it appears the cyclone has completed 
its transition to a post-tropical cyclone. Despite these structural 
changes, nearby ship observations indicate Ernesto remains a 
powerful cyclone with storm-force winds in its southern semicircle. 
Based on these observations, the initial intensity is set at 60 kt. 

The post-tropical cyclone is moving quickly northeastward (055/32 
kt) within the flow between a deep-layer trough over the north 
Atlantic and a subtropical ridge over the central Atlantic. An even 
faster east-northeastward motion is forecast through Wednesday as 
the cyclone remains embedded within strong steering currents. The 
system is forecast to merge with a frontal system and become 
extratropical by tonight, and the low should dissipate on Wednesday 
over the northeastern Atlantic. Although some weakening is expected 
during the next day or so, the cyclone will maintain a large wind 
field to the south of its center.

This is the last NHC advisory on Ernesto. 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
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/1500Z 49.0N  44.7W   60 KT  70 MPH...POST-TROPICAL
 12H  21/0000Z 50.5N  36.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 24H  21/1200Z 52.8N  23.3W   40 KT  45 MPH...POST-TROP/EXTRATROP
 36H  22/0000Z...DISSIPATED
 
$$
Forecaster Reinhart