000 WTNT45 KNHC 240848 TCDAT5 Hurricane Tammy Discussion Number 24 NWS National Hurricane Center Miami FL AL202023 500 AM AST Tue Oct 24 2023 Tammy's satellite depiction has improved slightly compared to the sheared convective pattern from yesterday evening. The latest infrared satellite imagery depicts convective bursts are once again wrapping around the southern portion of the system. Earlier microwave imagery showed a well organized low-to mid-level circulation. The most recent TAFB Dvorak satellite estimate held steady at T4.0/65kt, which supports maintaining an initial intensity of 65 kt for this advisory. The hurricane is currently moving northeastward, and should continue this motion for the next day or two. A mid-latitude trough approaching the system from the northwest will cause Tammy to begin to move more northward during the middle of the forecast period. It is after this point, the model guidance becomes increasingly divergent. Models are split on whether another mid-latitude trough will cause the system to accelerate east to northeastward, or have Tammy not being picked up by this trough and move the system westward to southwestward under a building mid-level ridge. The GFS has trended towards the west-southwest track scenario, closer to the ECMWF. Therefore, the NHC forecast track, which already favored the ECMWF solution, remains similar to the previous advisory and is close to a blend of GFS and ECMWF. There is considerably better agreement among most of the intensity guidance, which indicates slight strengthening is possible during the next day or two, as Tammy interacts with an upper-level trough. After 48 hours the system should begin to weaken and start to transition into a post-tropical cyclone. The latest model simulated satellite imagery depicts that this process is expected to be complete in about 60 h, though Tammy will likely continue to produce gale-to storm-force winds for several days even after this transition occurs. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 23.7N 62.8W 65 KT 75 MPH 12H 24/1800Z 24.5N 61.8W 70 KT 80 MPH 24H 25/0600Z 25.9N 60.3W 75 KT 85 MPH 36H 25/1800Z 27.9N 59.0W 75 KT 85 MPH 48H 26/0600Z 29.5N 58.9W 70 KT 80 MPH 60H 26/1800Z 31.0N 59.7W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 27/0600Z 31.7N 60.9W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 28/0600Z 32.4N 62.8W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 29/0600Z 32.8N 64.8W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Kelly