000 WTNT41 KNHC 311451 TCDAT1 HURRICANE FRED DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062015 1100 AM AST MON AUG 31 2015 Visible satellite pictures and earlier microwave data indicate that Fred has a well-defined inner core. The outer banding that was noted yesterday is no longer evident, and the hurricane is quite compact. A well-defined eye was evident in both a 0904 UTC SSMIS and 1121 UTC AMSU microwave overpasses. The initial intensity is raised to 75 kt, which is between the latest objective and subjective satellite estimates from UW/CIMSS and TAFB, respectively. Satellite data suggest that the eye of Fred passed just southwest of Boa Vista Island in the Cape Verde Islands, however the northeastern eyewall likely moved over a portion of that island just before 1200 UTC this morning. The sea surface temperatures along the path of Fred are beginning to decrease, however, the vertical shear is expected to remain quite low for another 12 hours or so. Little change in strength is expected today. By Tuesday, Fred will be over SSTS of around 26C and southwesterly shear is forecast to increase. This should cause gradual weakening, and a further increase in shear and a drier, more stable air mass should cause a faster rate of decay after 36 hours. The tropical cyclone is now forecast to become a tropical depression in about 4 days, and degenerate to a remnant low by the end of the forecast period. Fred continues to move northwestward at about 10 kt. The hurricane should maintain a northwestward heading during the next 12 to 24 hours. During this time, the center of Fred is expected to pass over or very close to the northwestern Cape Verde Islands of Sao Nicolou, Santa Luzuia, Sao Vicente, and Sao Antao. On Tuesday, a west- northwestward turn is predicted as a mid-level ridge builds to the north of the cyclone. Fred should then maintain a west-northwestward heading during the remainder of the forecast period. The NHC track remains on the south side of the guidance envelope, in best agreement with a consensus of the typically reliable GFS and ECMWF models. According to the official Atlantic tropical cyclone record, which begins in 1851, Fred is the first hurricane to pass through the Cape Verde Islands since 1892. We caution, however, that the database is less reliable prior to the satellite era (mid 1960s onward). Please note that the track/cone graphic, an automatically generated product, does not have the capability of displaying warnings for the Cape Verde Islands. FORECAST POSITIONS AND MAX WINDS INIT 31/1500Z 16.4N 23.7W 75 KT 85 MPH 12H 01/0000Z 17.3N 25.1W 70 KT 80 MPH 24H 01/1200Z 18.6N 26.9W 65 KT 75 MPH 36H 02/0000Z 19.6N 28.8W 60 KT 70 MPH 48H 02/1200Z 20.3N 30.6W 50 KT 60 MPH 72H 03/1200Z 21.4N 33.8W 40 KT 45 MPH 96H 04/1200Z 22.5N 37.5W 30 KT 35 MPH 120H 05/1200Z 24.0N 41.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown