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| #1068725 (Received by flhurricane at: 4:51 AM 06.Nov.2021) TCDAT1 Tropical Storm Wanda Discussion Number 26 NWS National Hurricane Center Miami FL AL212021 900 AM GMT Sat Nov 06 2021 Wanda`s convective structure has continued to evolve this morning, with two earlier bands situated east and west of the well-defined center now having consolidated into a solid band of convection with cloud tops of -50C to -57C wrapping around the eastern semicircle. The initial intensity remains 45 kt for this advisory based on continuity with earlier 40-45 kt ASCAT data and the recently improved convective structure. The initial motion estimate is southward or 180/04 kt. Wanda is expected to slow down further this morning and then turn sharply northeastward this afternoon as a narrow mid-/upper-level shortwave ridge passes to the north of the cyclone. A strong deep-layer trough and associated frontal system are then forecast to approach Wanda from the west by tonight, causing the cyclone to accelerate northeastward on Sunday and Monday. The front is forecast to catch up with Wanda in the 36-48-h period, resulting in extratropical transition before the system is absorbed by a large, deepening extratropical cyclone over the northern Atlantic early next week. The latest NHC model guidance is in excellent agreement on this developing forecast track scenario, and the official forecast track lies very near the the middle of the tightly packed simple- and corrected-consensus guidance envelope. Wanda`s is now over what will be the warmest water for the remainder of the cyclone`s lifetime. The deep-layer shear is forecast to remain around 10-15 kt for the next 24 h or so, while colder aloft overspreads the cyclone, creating a little more instability. This combination of positive environmental factors should continue to produce deep convection near Wanda`s center, possibly resulting in some slight strengthening before the system becomes an extratropical cyclone. The new NHC intensity forecast is basically identical to the previous advisory, and closely follows a blend of the various intensity consensus models. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 37.4N 38.3W 45 KT 50 MPH 12H 06/1800Z 37.5N 37.7W 45 KT 50 MPH 24H 07/0600Z 39.4N 35.0W 45 KT 50 MPH 36H 07/1800Z 43.6N 29.5W 50 KT 60 MPH 48H 08/0600Z 48.7N 22.2W 50 KT 60 MPH...POST-TROP/EXTRATROP 60H 08/1800Z 54.2N 12.8W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 09/0600Z...DISSIPATED $$ Forecaster Stewart |