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Tropical Storm Fred Forecast Discussion Number 25
2021-08-15 22:36:01| National Hurricane Center (Atlantic)
Issued at 400 PM CDT Sun Aug 15 2021 000 WTNT41 KNHC 152035 TCDAT1 Tropical Storm Fred Discussion Number 25 NWS National Hurricane Center Miami FL AL062021 400 PM CDT Sun Aug 15 2021 Satellite imagery indicates that Fred has become a little better organized this afternoon. The low-level circulation has become better defined, and there is a burst of central convection with additional outer banding in the eastern semicircle. A ship near the outer band north of the center reported 40-kt winds, so the initial intensity is increased to 40 kt. After the re-formation phase this morning, Fred appears to have resumed a north-northwestward motion of 330/9. The track guidance shows this motion continuing for another 12 h or so, followed by a turn toward the north that would bring the center to the coast of the Florida Panhandle in 24-36 h. A general north-northeastward motion is likely after 36 h until the system dissipates. The track guidance has shifted eastward again, this time due to the models forecasting an earlier turn to the north and a more east-of-north motion after landfall. The new NHC forecast track also is shifted a little to the east, but after 24 h it lies a little to the west of the various consensus models. Upper-level southwesterly flow between a trough to the north and northwest of Fred and an anticyclone to the southeast of the storm should keep the tropical cyclone in moderate southwesterly vertical shear until landfall. However, the intensity guidance continues to forecast strengthening, and the GFS, HWRF, and HMON show a stronger Fred at landfall than they did 6 h ago. Based on that and the increased current intensity, the pre-landfall intensities have been nudged upward. After landfall, Fred should quickly weaken and dissipate as it moves into the Tennessee Valley just after 60 h. Users are reminded not to focus on the exact forecast track of Fred, since rainfall, storm surge, and wind hazards will extend over an area well east of the center. KEY MESSAGES: 1. Today through Tuesday, heavy rainfall could lead to flash, urban, small stream, and isolated river flooding impacts across portions of southern Florida, the Big Bend and Panhandle of Florida, southeast Alabama, portions of Georgia, and the western Carolinas. From Tuesday onward, heavy rain and flood impacts could continue 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. Dangerous storm surge inundation is possible along portions of the coast of the Florida Panhandle and the Florida Big Bend region, and a Storm Surge Warning is in effect for this area. Interests in these areas should follow any advice given by local officials. 3. Tropical storm conditions are expected in the Tropical Storm Warning area in the Florida Panhandle beginning on Monday. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 26.8N 85.3W 40 KT 45 MPH 12H 16/0600Z 27.8N 86.0W 45 KT 50 MPH 24H 16/1800Z 29.5N 86.1W 50 KT 60 MPH 36H 17/0600Z 31.3N 86.0W 35 KT 40 MPH...INLAND 48H 17/1800Z 33.3N 85.5W 25 KT 30 MPH...INLAND 60H 18/0600Z 35.8N 84.3W 20 KT 25 MPH...POST-TROP/INLAND 72H 18/1800Z...DISSIPATED $$ Forecaster Beven
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Category:Transportation and Logistics