Tropical Storm Leslie Forecast Discussion

000
WTNT43 KNHC 110232
TCDAT3

Tropical Storm Leslie Discussion Number  35
NWS National Hurricane Center Miami FL       AL132024
1100 PM AST Thu Oct 10 2024

Leslie's center continues to be well exposed to the north of the 
convection, as northerly wind shear continues to impact the system. 
A recent scatterometer pass depicted winds of 50-55 kt. Satellite 
intensity estimates from TAFB, SAB and UW-CIMSS have come down this 
cycle and range from 45-55 kt which is in good agreement with the 
scatterometer pass. Therefore, the initial intensity for this 
advisory is lowered to 55 kt.

The storm is within a rather hostile environment with strong 
northerly shear displacing the convection from the center, and this 
shear is expected to persist over the next few days. Leslie is also 
dealing with very dry mid-levels as is depicted on GOES-16 water 
vapor imagery and the drier airmass continues along the forecast 
track. Models differ on the type of post-tropical system Leslie will 
eventually become, with the possibilities being either a remnant low 
or an extra-tropical low. The NHC forecast calls for the system to 
become a remnant low  in 48 h with model simulated satellite 
depicting Leslie will fail to produce organized deep convection 
within the harsh environment.  However, if the system is able to 
continue to produce convection for the next 36- 48 h, Leslie will 
approach a frontal zone and take on some frontal characteristics and 
become extratropical at that time. Either way, by day 4, the 
post-tropical low is forecast to dissipate into a open trough.

Leslie is moving north-northwestward, or 345/8 kt. Models are in 
fairly good agreement that a turn to the north will occur early 
Friday as the storm rounds the edge of the subtropical ridge located 
over the eastern Atlantic. The system will then turn northeastward 
with an increase in forward speed through the weekend. There was a 
slight left shift in the latest forecast guidance, as well as some 
along track spread. The latest NHC forecast was nudged left and is a 
little faster than the previous, near the simple consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  11/0300Z 24.4N  51.2W   55 KT  65 MPH
 12H  11/1200Z 25.9N  50.7W   45 KT  50 MPH
 24H  12/0000Z 28.4N  49.0W   40 KT  45 MPH
 36H  12/1200Z 31.5N  45.4W   35 KT  40 MPH
 48H  13/0000Z 34.6N  40.0W   35 KT  40 MPH...POST-TROPICAL
 60H  13/1200Z 36.6N  34.2W   35 KT  40 MPH...POST-TROPICAL
 72H  14/0000Z 37.1N  29.3W   30 KT  35 MPH...POST-TROPICAL
 96H  15/0000Z...DISSIPATED

$$
Forecaster Kelly