000 WTPZ42 KNHC 272032 TCDEP2 TROPICAL STORM FRANK DISCUSSION NUMBER 25 NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016 200 PM PDT WED JUL 27 2016 Frank has continued its weakening trend with only a small area of convection now displaced to the northwest of the low-level center. Although subjective and objective satellite intensity estimates support an intensity of about 60 kt, the initial intensity has been lowered to 50 kt based on a partial ASCAT-B scatterometer pass that showed winds of only about 40 kt in the eastern semicircle. Even though the western half of the cyclone was not sampled, it is assumed that some stronger winds exist in that part of the circulation, but not as strong as the satellite estimates due to the cooler waters creating a more stable boundary layer. The initial motion estimate is now 295/09 kt. Frank should move west-northwestward for the next 24 hours or so before turning westward by 36 hours after the cyclone degenerates into a shallow remnant low, which will be steered by the low-level easterly trade wind flow. The new NHC model guidance is in good agreement on this track scenario, although there is significant cross-track spread in the models after 48 hours. The official forecast track is similar to the previous advisory track and lies a little south of the consensus track model TVCN. Microwave imagery indicates that Frank's circulation has a northwestward tilt due to some southeasterly mid-level wind shear. The cyclone is also moving over sub-24C SSTs at this time, and cooler waters lie ahead of Frank. The combination of increasing shear, decreasing water temperatures, and a drier and more stable airmass should result in rapid weakening during the next 24 hours. Therefore, Frank is forecast to degenerate into a remnant low on Thursday and dissipate on Saturday. The official intensity forecast follows the intensity consensus model IVCN. FORECAST POSITIONS AND MAX WINDS INIT 27/2100Z 23.1N 121.8W 50 KT 60 MPH 12H 28/0600Z 23.8N 122.9W 40 KT 45 MPH 24H 28/1800Z 24.5N 124.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 29/0600Z 24.9N 125.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 29/1800Z 24.9N 126.1W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 30/1800Z 24.4N 128.0W 15 KT 15 MPH...POST-TROP/REMNT LOW 96H 31/1800Z...DISSIPATED $$ Forecaster Stewart