Tropical Storm Isaac Discussion Number  17
NWS National Hurricane Center Miami FL       AL102024
300 AM GMT Mon Sep 30 2024

Isaac's expected transition to an extratropical cyclone continues. 
The tropical storm's cloud pattern has become asymmetrical, with 
cold clouds limited mostly to the north of the surface center, and 
it is beginning to take the form of an extratropical rain shield. 
Partial ASCAT data indicated maximum winds of 45-50 kt, supporting 
an intensity of 55 kt after accounting for undersampling. This also 
agrees with the most recent tropical Dvorak analysis from TAFB.

The tropical storm should become fully extratropical later today. 
Models unanimously indicated that Isaac will continue to gradually 
spin down as a post-tropical low during the next several days. By 
96 h, the center of Isaac is expected to become poorly-defined as 
it interacts with another large non-tropical low pressure system 
over the north Atlantic. 

Models are in reasonably good agreement for Isaac's track forecast. 
It should stay on a generally northeastward track for the next day 
or so. Beyond that time, there is some disagreement on exactly how 
soon Isaac's post-tropical remnants will turn north-northeastward, 
however all of the guidance shows the same generally idea that Isaac 
will turn toward a broad trough over the north Atlantic. No 
significant changes were made to the NHC forecast, which is based on 
the IVCN consensus for intensity and the TVCN consensus for the 
track.

FORECAST POSITIONS AND MAX WINDS

INIT  30/0300Z 44.4N  32.8W   55 KT  65 MPH
12H  30/1200Z 45.1N  30.1W   50 KT  60 MPH...POST-TROP/EXTRATROP
24H  01/0000Z 46.7N  26.4W   45 KT  50 MPH...POST-TROP/EXTRATROP
36H  01/1200Z 48.6N  24.1W   40 KT  45 MPH...POST-TROP/EXTRATROP
48H  02/0000Z 50.7N  23.1W   40 KT  45 MPH...POST-TROP/EXTRATROP
60H  02/1200Z 52.4N  22.4W   35 KT  40 MPH...POST-TROP/EXTRATROP
72H  03/0000Z 54.4N  20.8W   35 KT  40 MPH...POST-TROP/EXTRATROP
96H  04/0000Z...DISSIPATED

$$
Forecaster D. Zelinsky