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| #1060765 (Received by flhurricane at: 5:11 PM 08.Sep.2021) TCDAT3 Tropical Storm Mindy Discussion Number 1 NWS National Hurricane Center Miami FL AL132021 400 PM CDT Wed Sep 08 2021 Through the day, the area of disturbed weather in the northeastern Gulf of Mexico has gradually become better organized on geostationary satellite and Doppler radar imagery. Earlier, a 1515 UTC ASCAT-C pass found a number of southwesterly wind retrievals in the 30-kt range on the southeast side of the formative circulation. The ASCAT-C Ambiguities at that time also hinted that a very small closed circulation was trying to develop along the edge of these stronger winds. Since that time, a well-defined circulation become evident on KEVX Doppler-radar with inbound velocities occasionally nearing 40-45 kt to the southeast of the radar center. These Doppler-radar winds have been increasing over the past couple of hours as the center moves closer to the radar and I am reasonably confident this circulation is now surface based. Just in the last hour or so, NOAA buoy 42039 reported a peak 1-minute sustained wind of 35 kt just southeast of the center, confirming the system now has tropical storm force winds. Thus, advisories are being initiated on tropical storm Mindy with maximum sustained wind of 35 kt. The most recent estimated motion following the center on radar is to the northeast at 050/18 kt. The track guidance is in good agreement that this quick motion should continue with a gentle shift to the east-northeast in the next 24-36 hours as the system is under the influence of a deep-layer mid-latitude trough moving across the eastern United States. On the current heading, the center of Mindy should move inland over the Florida Panhandle in the next 6-12 hours and then already be offshore of the southeastern United States by 24 hours. A gradual slowdown is expected thereafter as the cyclone is left behind by this mid-latitude trough and also becomes vertically shallow. Little intensification is expected prior to landfall, with land interaction resulting in Mindy weakening back to a depression by 24 hours. Conditions do not appear favorable for restrengthening off the southeastern United States as shear is forecast to increase above 30 knots in 24 hours. This shear will likely strip away from remaining convection, and both the ECMWF and GFS simulated IR brightness temperatures suggest Mindy should become a remnant low in the day 2-3 period. This remnant low is forecast to open up into a trough shortly thereafter. Key Messages: 1. Mindy is expected to produce heavy rainfall from the Florida Panhandle into southern portions of Georgia and South Carolina through Thursday morning. This rainfall may produce isolated to scattered flash, urban, and small stream flooding. 2. Tropical storm conditions are expected through tonight in portions of the Florida Panhandle where a Tropical Storm Warning is in effect. FORECAST POSITIONS AND MAX WINDS INIT 08/2100Z 29.0N 86.3W 35 KT 40 MPH 12H 09/0600Z 30.3N 84.1W 35 KT 40 MPH...INLAND 24H 09/1800Z 31.3N 80.0W 30 KT 35 MPH...OVER WATER 36H 10/0600Z 32.3N 75.6W 30 KT 35 MPH 48H 10/1800Z 32.9N 72.7W 30 KT 35 MPH 60H 11/0600Z 33.4N 69.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 11/1800Z 33.3N 68.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 12/1800Z...DISSIPATED $$ Forecaster Papin |