Hurricane Leslie Forecast Discussion

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WTNT43 KNHC 101433
TCDAT3

Hurricane Leslie Discussion Number  33
NWS National Hurricane Center Miami FL       AL132024
1100 AM AST Thu Oct 10 2024

The satellite presentation of Leslie has degraded since the previous 
advisory.  Strong northerly wind shear has been pushing most of the 
convection to the south side of the low-level center.  The most 
recent GOES-16 images suggest that the low-level center is likely 
just barely underneath the northern edge of the central dense 
overcast.  The latest subjective current intensity values from TAFB 
and SAB are still 90 kt due to continuity constraints, but the 
latest ADT and AiDT intensity estimates from UW-CIMSS have decreased 
down to 72 kt.  The intensity is set to 80 kt, as a blend of all the 
estimates.

Leslie has already entered the strong northerly shear zone that has 
been advertised in previous discussions, and the guidance indicates 
that the shear will continue to increase to over 40 kt over the next 
12 to 24 h.  Shear that strong, combined with the dry environment 
that Leslie is embedded within, is likely to lead to steady to rapid 
weakening.  The NHC forecast calls for Leslie to weaken by 35 kt 
over the next 36 h, in good agreement with the HCCA corrected 
consensus, HAFS models, and the intensity consensus.  After that, 
the models hold on to Leslie, and there is quite a bit of 
uncertainty in the timing of when Leslie will become post-tropical.  
GFS and ECMWF simulated satellite imagery indicate that puffs of 
convection could continue through the weekend.  The cyclone is also 
likely to interact with an approaching frontal system by Sunday.  
The NHC forecast continues to call for Leslie to become 
post-tropical by day 3.

The initial motion is estimated to be west-northwestward, or 300/6 
kt.  Model guidance is in excellent agreement that a northward turn 
will happen very soon as Leslie moves around the southwestern 
periphery of a subtropical ridge over the eastern Atlantic.  On 
Friday and Friday night, the hurricane should speed up and turn to 
the northeast, followed by an east-northeastward turn as it 
accelerates further over the weekend.  The latest NHC track forecast 
is slightly west of the previous one during the first 48 hours of 
the forecast, and nearly identical to the previous forecast 
thereafter.  The official forecast is in best agreement with the 
TVCA consensus.


FORECAST POSITIONS AND MAX WINDS

INIT  10/1500Z 23.2N  50.4W   80 KT  90 MPH
 12H  11/0000Z 24.0N  50.9W   70 KT  80 MPH
 24H  11/1200Z 25.7N  50.6W   55 KT  65 MPH
 36H  12/0000Z 28.1N  48.9W   45 KT  50 MPH
 48H  12/1200Z 30.8N  45.9W   45 KT  50 MPH
 60H  13/0000Z 33.3N  41.0W   45 KT  50 MPH
 72H  13/1200Z 35.2N  35.6W   45 KT  50 MPH...POST-TROPICAL
 96H  14/1200Z 36.6N  25.9W   35 KT  40 MPH...POST-TROPICAL
120H  15/1200Z...DISSIPATED

$$
Forecaster Hagen