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Remnants of Fred Forecast Discussion Number 22
2021-08-15 04:48:46| National Hurricane Center (Atlantic)
Issued at 1100 PM EDT Sat Aug 14 2021 000 WTNT41 KNHC 150248 TCDAT1 Remnants Of Fred Discussion Number 22 NWS National Hurricane Center Miami FL AL062021 1100 PM EDT Sat Aug 14 2021 Deep convection has increased in association with the remnants of Fred this evening with some lose banding noted in both satellite imagery and radar data from Key West. Satellite imagery and surface observations also indicate that the circulation has become a little better defined since this afternoon, but the system still lacks a well-defined center. Therefore, the system has not regained tropical cyclone status yet. The initial intensity remains 30 kt and is based on a few buoy and C-MAN observations over the southeastern Gulf of Mexico and the Lower Florida Keys which have reported peak winds of 25-30 kt over the past several hours. The C-MAN site on Sand Key has reported slightly stronger winds, but that site is elevated. The system has moved little during the past several hours, and since it lacks a well-defined center, the initial motion estimate is a highly uncertain 300/08 kt. The disturbance is expected to begin a more definitive northwestward motion overnight or Sunday morning as it moves around the western extent of a subtropical ridge over the western Atlantic. The system is forecast to turn northward on Monday as it nears the northern Gulf of coast. Although the track guidance is in good agreement on the overall motion scenario, there is some cross-track spread that appears to be related to where the center re-forms in the short term. Overall there was some eastward shift to the guidance envelope and the official forecast was nudged in that direction, but it still lies to the west of the consensus aids. The NHC track forecast is closest to the GFEX track, which is a consensus of the typically reliable GFS and ECMWF models. The upper-level trough over the eastern Gulf of Mexico is forecast to weaken and move northward during the next 12-24 hours. This should allow for a somewhat more conducive environment for the system to regain tropical cyclone status and strengthen on Sunday. However, continued moderate southwesterly vertical wind shear is likely to hinder significant development, and the NHC intensity forecast only calls for gradual strengthening through 36-48 hours. After landfall, the system is forecast to weaken rapidly and the global models indicate the circulation will dissipate by 96 hours. Although no coastal watches or warnings are currently in effect, the National Hurricane Center will continue 6-hourly advisories on the remnants of Fred in anticipation of re-development. Watches are very likely to be required for a portion of the northern Gulf coast early Sunday, and warnings may be required later in the day. KEY MESSAGES: 1. Today through Monday, heavy rainfall could lead to areal, urban, and small stream flooding impacts, and cause new and renewed river flooding across southern Florida, the Big Bend, and Panhandle. From Monday onward, heavy rain and flood impacts could extend into other portions of the Southeast and into the southern and central Appalachians and Piedmont as Fred interacts with a front in the area. 2. Fred is forecast to regenerate as a tropical cyclone over the Gulf of Mexico on Sunday, and bring a risk of tropical storm conditions to portions of the northern Gulf coast, especially from coastal Mississippi to the Florida Panhandle beginning on Monday. Watches will likely be required for a portion of this area early Sunday, and warnings may be required later in the day. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 23.8N 84.3W 30 KT 35 MPH 12H 15/1200Z 25.3N 85.7W 35 KT 40 MPH...TROPICAL CYCLONE 24H 16/0000Z 26.8N 86.9W 40 KT 45 MPH 36H 16/1200Z 28.3N 87.8W 45 KT 50 MPH 48H 17/0000Z 29.7N 88.0W 45 KT 50 MPH 60H 17/1200Z 31.4N 87.9W 30 KT 35 MPH...INLAND 72H 18/0000Z 33.1N 87.6W 20 KT 25 MPH...INLAND 96H 19/0000Z...DISSIPATED $$ Forecaster Brown
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