000 WTNT41 KNHC 030235 TCDAT1 TROPICAL STORM FRED DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062015 1100 PM AST WED SEP 02 2015 The cluster of thunderstorm activity that developed before the previous advisory has persisted, with cloud tops colder than -80C seen to the northeast of the partly exposed low-level center. Satellite intensity estimates are unchanged since the previous advisory, so the initial intensity remains 35 kt. There is little change in either the forecast guidance or the forecast track since the last advisory. Fred should move west-northwestward to the south of a low- to mid-level ridge over the eastern Atlantic during the next 2-3 days. After that time, the cyclone should turn northwestward, and then northward between the ridge and a low- to mid-level trough over the central Atlantic. The new forecast track lies near the center of the guidance envelope. Fred is experiencing 25-30 kt of westerly vertical wind shear, and the dynamical models suggest this will continue for the next 60-72 hours. This, in combination with dry air entraining into the cyclone, should cause it to degenerate into a remnant low in 24-36 hours, if not earlier. After 72 hours, the remnants of Fred are expected to reach an environment of warmer sea surface temperatures, decreasing shear, and increasing moisture. In theory, this could allow the system to regenerate. However, while the dynamical models show the remnant low persisting through 120 hours, none of them show any significant intensification in the more favorable environment. Based on this, the forecast will continue to show a weak remnant low through 120 hours. FORECAST POSITIONS AND MAX WINDS INIT 03/0300Z 20.6N 32.7W 35 KT 40 MPH 12H 03/1200Z 21.2N 33.9W 35 KT 40 MPH 24H 04/0000Z 21.8N 35.4W 30 KT 35 MPH 36H 04/1200Z 22.2N 37.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 05/0000Z 22.6N 38.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 06/0000Z 23.5N 41.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 07/0000Z 26.0N 42.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 08/0000Z 28.5N 41.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven