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#872582 (Received by flhurricane at: 4:35 PM 20.Aug.2016) TCDAT1 TROPICAL STORM FIONA DISCUSSION NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062016 500 PM AST SAT AUG 20 2016 Fiona's center has again become partially exposed this afternoon in response to strong southwesterly shear of about 30 kt. A blend of the latest Dvorak estimates from TAFB and SAB, and ADT values from CIMSS at the University of Wisconsin, support holding the initial intensity at 35 kt for this advisory. Continued hostile upper-level winds along with dry air along the path of the storm should induce a weakening trend, and Fiona is still expected to weaken to a tropical depression tonight or Sunday. The ECMWF model opens this system into a trough during the next few days, while some of the other models hold onto a closed low through the period. If Fiona survives the strong shear during the next 48 hours, there is a possibility that the system could continue as a weak tropical cyclone for the next several days. The official intensity forecast is similar to the previous one, and leans toward the ECMWF model solution. Fiona has jogged a bit to the right, and it is now moving northwestward at about 13 kt. The forecast reasoning remains unchanged from the earlier forecasts, as the low- to mid-level subtropical ridge over the central Atlantic should keep Fiona moving west-northwestward for the next several days. The NHC track forecast is similar to the previous one and is in best agreement with the multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 21.2N 49.1W 35 KT 40 MPH 12H 21/0600Z 22.1N 51.0W 35 KT 40 MPH 24H 21/1800Z 23.1N 53.6W 30 KT 35 MPH 36H 22/0600Z 24.1N 56.2W 30 KT 35 MPH 48H 22/1800Z 25.0N 58.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 23/1800Z 27.0N 62.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 24/1800Z 29.5N 65.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 25/1800Z...DISSIPATED $$ Forecaster Cangialosi/Latto |