Subtropical Storm Wanda Forecast Discussion Number 6
ActuCyclone
1 novembre 2021
000 WTNT41 KNHC 010927 CCA TCDAT1 Subtropical Storm Wanda Discussion Number 6...Corrected NWS National Hurricane Center Miami FL AL212021 900 AM GMT Mon Nov 01 2021 Corrected initial position Wanda is now located to the west of the axis of the upper-level trough that it is embedded in. As a result, significant northerly vertical wind shear has developed over the storm, and between this and continuing dry air entrainment the associated convection is less organized than 24 h ago. Various subjective and objective satellite intensity estimates are in the 40-50 kt range, and based on continuity from earlier ASCAT data the initial intensity is held at 45 kt. After the earlier southwestward motion, Wanda is now turning southeastward with the initial motion of 125/6. The storm and the upper-level trough should move northeastward later today and then northward by 36-48 h as southerly flow between a large mid-latitude trough over the northwestern Atlantic and a ridge east of Wanda becomes the dominant steering mechanism. After 72 h, another mid-latitude ridge is expected to build between Wanda and the western Atlantic trough, and as a result the cyclone is expected to turn eastward and then southward. The latest track guidance shows a more northward motion than the previous guidance between 36-60 h, and a more southward motion after 96 h. The new forecast track has been nudged in those directions. The intensity guidance suggests little change in strength during the next several days as dry air and relatively cool SSTs continue to affect the system. However, the current shear is expected to decrease during the next 24-36 h, and this should help the system to transition to a tropical cyclone. By 120 h, Wanda is expected to become a post-tropical low as cooler sea surface temperatures and an even dryer air mass cause the convection to dissipate. The new intensity forecast is unchanged from the previous forecast. FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 34.5N 43.9W 45 KT 50 MPH 12H 01/1800Z 34.3N 43.3W 45 KT 50 MPH 24H 02/0600Z 34.9N 42.1W 45 KT 50 MPH...TROPICAL CYCLONE 36H 02/1800Z 36.2N 41.3W 45 KT 50 MPH 48H 03/0600Z 38.2N 40.9W 45 KT 50 MPH 60H 03/1800Z 40.1N 40.7W 45 KT 50 MPH 72H 04/0600Z 41.5N 40.0W 45 KT 50 MPH 96H 05/0600Z 43.0N 36.5W 45 KT 50 MPH 120H 06/0600Z 41.0N 33.5W 40 KT 45 MPH...POST-TROPICAL $$ Forecaster Beven