Show Selection: |
#1108434 (Received by flhurricane at: 10:42 PM 22.Sep.2022) TCDAT3 Tropical Storm Gaston Discussion Number 11 NWS National Hurricane Center Miami FL AL082022 300 AM GMT Fri Sep 23 2022 Gaston`s cloud pattern is showing signs of disruption by westerly shear with the center located near the western edge of the main area of convection. This was confirmed by a recent scatterometer overpass, which showed that the intensity was, somewhat surprisingly, still near 55 kt. This intensity is also in agreement with a Dvorak classification from TAFB, and so the advisory`s initial wind speed is held at that value. The storm has continued to slow its forward speed, with the latest initial motion estimated to be eastward at around 10 kt. During the next day or so, Gaston is expected to move on a clockwise loop along the southern side of a blocking mid-level ridge. The official track forecast follows the multi-model consensus prediction. This is fairly close to the previous NHC forecast, except shifted a little northward in the latter part of the period. Gaston is expected to remain in an environment of dry air, over relatively cool SSTs, and under the influence of strong westerly shear for the next couple of days. These factors should lead to gradual weakening and loss of tropical characteristics in 48 hours or so. The official intensity forecast is similar to the previous one and is close to the latest Decay-SHIPS prediction. Key Messages: 1. Tropical storm conditions are occurring over portions of the western Azores, and will likely spread to the central Azores later today. 2. Gaston is expected to produce heavy rainfall over the western and central Azores today into Saturday. This rainfall may result in landslides and areas of flooding. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 41.0N 31.0W 55 KT 65 MPH 12H 23/1200Z 40.4N 29.4W 55 KT 65 MPH 24H 24/0000Z 39.3N 29.3W 50 KT 60 MPH 36H 24/1200Z 38.7N 30.4W 50 KT 60 MPH 48H 25/0000Z 38.9N 32.3W 50 KT 60 MPH...POST-TROPICAL 60H 25/1200Z 39.4N 34.4W 45 KT 50 MPH...POST-TROPICAL 72H 26/0000Z 39.8N 36.4W 40 KT 45 MPH...POST-TROPICAL 96H 27/0000Z 40.9N 38.0W 35 KT 40 MPH...POST-TROPICAL 120H 28/0000Z 41.5N 39.0W 35 KT 40 MPH...POST-TROPICAL $$ Forecaster Pasch |