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| #1153082 (Received by flhurricane at: 10:56 AM 16.Sep.2023) TCDAT4 Tropical Storm Margot Discussion Number 37 NWS National Hurricane Center Miami FL AL142023 300 PM GMT Sat Sep 16 2023 Margot's structure has continued to degrade, with the low level center now exposed on visible satellite imagery. Deep convection is mainly limited to the southern semicircle of the tropical storm. Dry air is also wrapping around the western and southern side of Margot. The subjective Dvorak intensity estimates from TAFB and SAB both support an initial intensity of 45 kt. Margot has maintained its southwestward heading and is moving slightly faster, with an initial estimate of 215/7 kt. Since the tropical storm has yet to turn due west, the official forecast shows a slightly larger clockwise loop around a mid-level ridge through 48 hours. This is on the eastern edge of the model consensus aids. As the mid-level ridge builds south-eastward, Margot is expected to turn back towards the east and potentially interact with a shortwave trough arriving from the northwest. Beyond 48 hours, the NHC forecast is slightly south of and slower than the previous forecast, closest to the HCCA consensus aid. Environmental conditions are not expected to improve, with moderate-to-strong northerly vertical wind shear, dry mid-level relative humidities, and sea surface temperatures of 26 Celsius or less through the forecast period. As a result, weakening is forecast in the near-term, and simulated satellite IR imagery from the GFS and ECMWF shows a notable lack of deep convection during this time. By Monday night, Margot is expected to begin interacting with a mid-latitude shortwave trough. This could allow for some slight re-intensification, as is shown in the official forecast. Margot is not expected to be absorbed by the trough and is forecast to degenerate into a post-tropical cyclone west of the Azores. FORECAST POSITIONS AND MAX WINDS INIT 16/1500Z 34.4N 38.7W 45 KT 50 MPH 12H 17/0000Z 34.1N 40.1W 40 KT 45 MPH 24H 17/1200Z 34.3N 41.7W 35 KT 40 MPH 36H 18/0000Z 35.1N 43.0W 35 KT 40 MPH 48H 18/1200Z 36.5N 42.9W 35 KT 40 MPH 60H 19/0000Z 37.9N 40.9W 40 KT 45 MPH 72H 19/1200Z 38.6N 37.8W 40 KT 45 MPH 96H 20/1200Z 37.8N 33.1W 30 KT 35 MPH...POST-TROPICAL 120H 21/1200Z 38.0N 30.1W 30 KT 35 MPH...POST-TROPICAL $$ Forecaster Mahoney/Bucci |
