Tropical Storm Leslie Forecast Discussion Number 8

By | October 4, 2024

000
WTNT43 KNHC 040845
TCDAT3

Tropical Storm Leslie Discussion Number   8
NWS National Hurricane Center Miami FL       AL132024
500 AM AST Fri Oct 04 2024

A 0421 UTC GMI microwave pass showed that Leslie has developed a 
well-defined low-level structure, along with what appears to be an 
attempt at an eyewall feature south of the center.  This asymmetry 
in the convection is the result of continued moderate shear out of 
the north-northeast.  ASCAT-C data from several hours ago showed 
several 44-kt wind barbs northwest of the center.  Given the 
typical undersampling of this instrument, and the storm's improved 
structure despite the shear, the initial intensity is estimated to 
be 50 kt.

The GMI and ASCAT passes helped immensely in locating Leslie's 
center, which is a little farther south than previously estimated.  
Leslie is moving slowly westward, or 270/5 kt, along the southern 
periphery of the subtropical ridge.  With the ridge expected to 
remain centered over the eastern Atlantic, Leslie is forecast to 
gradually turn west-northwestward later today and then toward the 
northwest in about 48 hours, with that motion continuing through 
the middle of next week.  The NHC track forecast is near a blend of 
the HCCA and TVCA consensus aids, and any differences from the 
previous prediction should be considered negligible.

The deep-layer shear affecting Leslie is likely to abate in about 
12 hours.  However, there are a few environmental features that 
could potentially limit Leslie's rate of intensification.  
Mid-level shear and dry air are shown to be the biggest negative 
factors in the SHIPS diagnostics, and Leslie may end up moving over 
Hurricane Kirk's cold wake.  Additional strengthening is still 
anticipated, however much of the intensity guidance has come down 
on this cycle.  The NHC intensity forecast is slightly lower than 
the previous forecast to follow this trend, but it lies near or 
above the highest intensity models for most of the forecast period.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z  9.8N  32.5W   50 KT  60 MPH
 12H  04/1800Z 10.1N  33.4W   55 KT  65 MPH
 24H  05/0600Z 10.5N  34.7W   60 KT  70 MPH
 36H  05/1800Z 11.0N  36.1W   70 KT  80 MPH
 48H  06/0600Z 11.8N  37.3W   75 KT  85 MPH
 60H  06/1800Z 13.0N  38.6W   80 KT  90 MPH
 72H  07/0600Z 14.5N  40.1W   85 KT 100 MPH
 96H  08/0600Z 17.5N  43.6W   90 KT 105 MPH
120H  09/0600Z 20.3N  47.2W   95 KT 110 MPH

$$
Forecaster Berg

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