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| #1067939 (Received by flhurricane at: 4:44 AM 31.Oct.2021) TCDAT1 Subtropical Storm Wanda Discussion Number 2 NWS National Hurricane Center Miami FL AL212021 900 AM GMT Sun Oct 31 2021 Satellite imagery indicates that the convection associated with Wanda has become better organized since the last advisory, with a convective band now wrapping more than halfway around the center. However, the cyclone remains embedded in a deep-layer baroclinic circulation, and based on this structure, the system is still a subtropical storm. Satellite intensity estimates are in the 40-50 kt range, and the intensity is set at a possibly conservative 45 kt. The initial motion is a little slower toward the east-southeast at 105/14 kt. As mentioned in the previous advisory, a slower east-southeast to southeast motion is expected during the next day or so as Wanda moves with the deep-layer trough that it is embedded within. After that time, the trough is expected to cut off, and Wanda will likely meander on Monday before turning sharply northward or northeastward by the middle of next week when the system moves in the flow between the cut off low and a building ridge. By the end of the forecast period, the cyclone is expected to turn northeastward in southwesterly mid-latitude flow. The new track guidance is similar to the previous guidance, but is a little slower after 72 h. Thus, the new forecast track is similar to the previous track and also slower in the later periods. Given the increasing organization, it is likely that Wanda will strengthen some during the next 24 h. After that, the intensity guidance suggests little change in strength through 48 h as the cyclone moves over sea surface temperatures of 24 C. Beyond 48 h, gradual weakening is expected as Wanda moves over colder waters, with the system expected to become post-tropical due to a lack of convection by 120 h. It should be noted that the GFS and UKMET suggest the possibility that Wanda could transition into a tropical storm by 48 h. However, due to the expectation that the cyclone will continue to remain embedded in a cold upper-level trough, the intensity forecast will not explicitly call for tropical transition at this time. FORECAST POSITIONS AND MAX WINDS INIT 31/0900Z 36.5N 43.9W 45 KT 50 MPH 12H 31/1800Z 36.2N 43.0W 50 KT 60 MPH 24H 01/0600Z 35.3N 42.8W 50 KT 60 MPH 36H 01/1800Z 34.6N 42.0W 50 KT 60 MPH 48H 02/0600Z 34.8N 40.7W 50 KT 60 MPH 60H 02/1800Z 36.2N 39.6W 50 KT 60 MPH 72H 03/0600Z 38.3N 39.0W 45 KT 50 MPH 96H 04/0600Z 43.0N 38.0W 45 KT 50 MPH 120H 05/0600Z 47.0N 32.5W 40 KT 45 MPH...POST-TROPICAL $$ Forecaster Beven |