000 WTNT43 KNHC 212031 TCDAT3 Tropical Storm Gaston Discussion Number 6 NWS National Hurricane Center Miami FL AL082022 Issued by the NWS Weather Prediction Center College Park MD 900 PM GMT Wed Sep 21 2022 There has been little change associated with Gaston during the past several hours. The system continues to produce an area of deep convection near the center and exhibits well-defined outflow over the western semicircle. However, drier air is entraining into the eastern portion of the circulation. The Dvorak CI-numbers from TAFB and SAB continue to support an initial intensity of 55 kt. Gaston continues to track northeastward over the north-central Atlantic, with the latest initial motion estimated to be 045/12 kt. Although there is no significant change to the forecast reasoning, there is a considerable amount of model spread in the details of the future steering pattern. An amplifying ridge associated with Fiona is expected to trap Gaston's circulation late this week and this weekend. This could result in a clockwise loop and an eventual turn westward. The new NHC track forecast is a little to the south and faster than the previous one, trending toward the latest consensus models. It appears that the opportunity for strengthening has ended. A slow weakening trend should begin in the next day or so when Gaston moves over cooler waters and into a region of drier air and slightly stronger westerly vertical wind shear. An approaching mid-level trough should aid in the system's transition to an extratropical cyclone in a couple of days or so. The NHC intensity forecast remains near the middle of the guidance envelope. Interests in the Azores should continue to monitor the forecast for Gaston. For additional information, see warnings and products issued by the meteorological service in the Azores. FORECAST POSITIONS AND MAX WINDS INIT 21/2100Z 39.0N 40.0W 55 KT 65 MPH 12H 22/0600Z 40.0N 37.4W 55 KT 65 MPH 24H 22/1800Z 40.8N 33.9W 55 KT 65 MPH 36H 23/0600Z 40.9N 31.2W 50 KT 60 MPH 48H 23/1800Z 40.4N 30.0W 50 KT 60 MPH 60H 24/0600Z 39.8N 30.1W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 24/1800Z 39.6N 31.1W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 25/1800Z 40.3N 34.7W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 26/1800Z 41.0N 37.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Cangialosi/Wegman/Carbin