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#927520 (Received by flhurricane at: 11:02 AM 28.May.2018) TCDAT1 Subtropical Storm Alberto Discussion Number 14 NWS National Hurricane Center Miami FL AL012018 1000 AM CDT Mon May 28 2018 Alberto has struggled to produce significant deep convection since early this morning, however, there are several bands of shallow convection that wrap around the eastern and northern portions of the circulation. The Air Force Reserve reconnaissance aircraft has not found winds as high as last evening, but has reported SFMR winds of 45 to 50 kt which support an initial intensity of 50 kt. The pressure has risen a couple of millibars with data from a recent center dropsonde supporting a minimum pressure of 992 mb. Since the primary convective bands are already moving onshore along the coast of the Florida panhandle, little change in strength is expected through landfall later today. After landfall, Alberto should quickly weaken and become a depression tonight or early Tuesday, then degenerate into a remnant low over the Tennessee Valley in about 36 hours. The latest couple of center fixes from the aircraft show that Alberto has jogged to the east this morning. The longer-term motion, however, is generally northward at about 7 kt. A northward to north-northwestward motion should bring the center onshore in the Florida panhandle this afternoon or evening. After landfall, the system should continue generally northward around the western portion of a mid-level ridge located over the western Atlantic. Before the system is absorbed by a frontal boundary over Canada late in the week, it should turn northeastward ahead of a trough moving through the central United States. The track guidance is in relatively good agreement, and only minor adjustments were needed to the previous NHC track forecast. KEY MESSAGES: 1. Heavy rainfall will lead to a significant risk of flash flooding across the Florida Panhandle, much of Alabama, and western Georgia through tonight, spreading northward into northern Georgia, the western Carolinas, and Tennessee on Tuesday. A risk of flooding and flash flooding will continue over central Cuba, the Florida Keys, and southern Florida today. 2. Hazardous storm surge is possible along portions of the eastern Gulf Coast today, including areas well east of the track of Alberto`s center. Residents in the storm surge watch area are encouraged to follow guidance given by their local government officials. 3. Tropical storm conditions are likely within portions of the tropical storm warning area today. 4. Dangerous surf and rip current conditions will continue to affect portions of the eastern and northern Gulf Coast through Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 29.5N 85.8W 50 KT 60 MPH 12H 29/0000Z 30.8N 86.1W 40 KT 45 MPH...INLAND 24H 29/1200Z 33.0N 86.6W 25 KT 30 MPH...INLAND 36H 30/0000Z 35.9N 87.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 30/1200Z 38.9N 87.1W 15 KT 15 MPH...POST-TROP/REMNT LOW 72H 31/1200Z 44.9N 84.8W 15 KT 15 MPH...POST-TROP/REMNT LOW 96H 01/1200Z 48.5N 78.5W 15 KT 15 MPH...POST-TROP/REMNT LOW 120H 02/1200Z...DISSIPATED $$ Forecaster Brown |