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| #1067973 (Received by flhurricane at: 11:06 AM 31.Oct.2021) TCDAT1 Subtropical Storm Wanda Discussion Number 3 NWS National Hurricane Center Miami FL AL212021 300 PM GMT Sun Oct 31 2021 Wanda is gradually taking on characteristics of a symmetric warm-core cyclone, with bands of organized convection now located across both the northern and southeastern portions of the circulation. The 500-mb heights are slowing rising, while some cirrus outflow is becoming evident to the north of the cyclone. Although Wanda is still considered a subtropical storm due to the presence of the surrounding baroclinic circulation and upper-trough, the baroclinic circulation has been getting more detached from the storm over time. Even though the convective structure continues to evolve, this convection has not been able to become more concentrated near the system`s core since last night. Therefore, the initial advisory intensity remains 45 kt, which is consistent with the latest average of the satellite intensity estimates from TAFB, and UW-CIMSS ADT and SATCON. The storm has slowed its forward motion and is now moving at 100/07 kt. A turn to the southeast is expected today as Wanda wobbles within the upper-level tropospheric trough that it is embedded within. The upper-trough is forecast to lift out on Monday, leaving Wanda within the weak steering flow near a cutoff mid-level trough. By Tuesday, a ridge is forecast to build to the east of the cyclone, resulting in a turn to the northeast or north, along with an increase in forward speed. By late this week, Wanda should accelerate northeastward within the southwesterly mid-latitude flow. The model guidance is in good agreement on this track scenario, and the latest NHC track forecast is very similar to the previous one. Despite being over sea surface temperatures below the ideal warmth to support a classic tropical cyclone, the colder-than-typical upper tropospheric temperatures over Wanda should continue to help support deep convection for the next few days. Therefore, some slight strengthening is possible during that time. As mentioned above, the upper-trough is expected to leave Wanda behind by Monday, which should allow the cyclone to complete a tropical transition by that time. Various global model solutions within the Florida State University cyclone phase evolution forecasts agree with this scenario taking place over the next 24 h. After 72 h, decreasing water temperatures in the path of Wanda should cause the cyclone to weaken and become post-tropical by the end of the 5-day forecast period. The latest NHC intensity forecast is unchanged from the previous one, with the only change being the tropical phase of Wanda beginning Monday. FORECAST POSITIONS AND MAX WINDS INIT 31/1500Z 36.4N 43.2W 45 KT 50 MPH 12H 01/0000Z 35.9N 42.8W 50 KT 60 MPH 24H 01/1200Z 34.9N 42.4W 50 KT 60 MPH...TROPICAL CYCLONE 36H 02/0000Z 34.8N 41.2W 50 KT 60 MPH 48H 02/1200Z 35.6N 40.0W 50 KT 60 MPH 60H 03/0000Z 37.4N 39.1W 50 KT 60 MPH 72H 03/1200Z 39.4N 38.7W 45 KT 50 MPH 96H 04/1200Z 43.4N 37.3W 45 KT 50 MPH 120H 05/1200Z 47.2N 30.0W 40 KT 45 MPH...POST-TROPICAL $$ Forecaster Latto |