Tropical Storm Isaac Discussion Number  18
NWS National Hurricane Center Miami FL       AL102024
900 AM GMT Mon Sep 30 2024

Isaac continues to show signs of transitioning into an extratropical 
cyclone.  The central convection has mostly dissipated, and the 
system is taking on more of a frontal appearance, with a 
zonally-oriented cloud and rain shield over the cyclone's northern 
semicircle.  The current intensity is kept at 55 kt in accordance 
with a Dvorak estimate from TAFB, although this is somewhat 
uncertain since Isaac no longer appears to be a true tropical 
cyclone.

The cyclone continues to move east-northeastward or at about 060/13 
kt within a southern branch of the mid-latitude westerlies.  Isaac 
is expected to turn toward the northeast during the next couple 
of days as it approaches a shortwave ridge just west of the 
British Isles.  The official track forecast has been nudged only 
slightly eastward in the 2-3 day time frame, towards the latest 
corrected dynamical model consensus.

Isaac is moving over cool waters and should complete its 
extratropical transition today.  The global models suggest that the 
system will gradually weaken during the next few days as it becomes 
absorbed within a larger low over the North Atlantic.  The official 
intensity forecast is similar to the previous NHC prediction.


FORECAST POSITIONS AND MAX WINDS

INIT  30/0900Z 44.7N  31.3W   55 KT  65 MPH
12H  30/1800Z 45.8N  28.1W   50 KT  60 MPH...POST-TROP/EXTRATROP
24H  01/0600Z 47.4N  25.1W   45 KT  50 MPH...POST-TROP/EXTRATROP
36H  01/1800Z 49.4N  23.3W   40 KT  45 MPH...POST-TROP/EXTRATROP
48H  02/0600Z 51.3N  22.3W   40 KT  45 MPH...POST-TROP/EXTRATROP
60H  02/1800Z 53.0N  21.2W   35 KT  40 MPH...POST-TROP/EXTRATROP
72H  03/0600Z 54.5N  20.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
96H  04/0600Z...DISSIPATED

$$
Forecaster Pasch