000 WTNT41 KNHC 302035 TCDAT1 TROPICAL STORM FRED DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062015 500 PM AST SUN AUG 30 2015 Fred has continued to strengthen this afternoon. A new burst of deep convection has developed over the center, with the CDO becoming more symmetric. Late afternoon visible satellite pictures also reveal increased banding in all quadrants. AMSR-2 and GCOM microwave data from late this morning indicated that Fred continues to exhibit a well-defined inner core with a closed low-level ring in the 37 GHz imagery. The initial intensity has been raised to 55 kt, which is in agreement with a subjective data T-number of 3.5 from TAFB and T3.4 from UW/CIMSS ADT. Fred is forecast to remain in a favorable environment characterized by very low vertical wind shear, warm water, and sufficient mid-level moisture during the next day or so. Therefore, additional strengthening is expected and the NHC forecast calls for Fred to become a hurricane tonight or early Monday. This is supported by the statistical guidance and the HWRF model which bring Fred to hurricane status. In about 36 hours, the tropical cyclone will be moving into a more hostile environment of increasing southwesterly shear, cooler sea surface temperatures, and a more stable air mass. This should result in weakening throughout the remainder of the forecast period, and the new NHC forecast weakens Fred to a tropical depression by 120 h. Fred has been moving faster than predicted today, and the initial motion estimate is 310/14 kt. The forecast track philosophy remains unchanged from before. The cyclone should move northwestward toward a break in the subtropical ridge during the next day or so. In a couple of days, Fred should turn west-northwestward as the ridge rebuilds to the north of the cyclone over the eastern and central Atlantic. The updated NHC track forecast is a little north of the previous advisory after 48 hours to be in better agreement with the GFEX (GFS and ECMWF) consensus model. 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 30/2100Z 14.4N 21.3W 55 KT 65 MPH 12H 31/0600Z 15.6N 22.8W 65 KT 75 MPH 24H 31/1800Z 16.9N 24.6W 70 KT 80 MPH 36H 01/0600Z 18.2N 26.3W 65 KT 75 MPH 48H 01/1800Z 19.2N 28.2W 60 KT 70 MPH 72H 02/1800Z 20.6N 31.7W 50 KT 60 MPH 96H 03/1800Z 21.8N 35.5W 40 KT 45 MPH 120H 04/1800Z 22.8N 39.0W 30 KT 35 MPH $$ Forecaster Brown