Tropical Storm Leslie Forecast Discussion Number 35
Issued at 1100 PM AST Thu Oct 10 2024 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
Issued at 1100 PM AST Thu Oct 10 2024
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
