Show Selection: |
#979733 (Received by flhurricane at: 11:03 PM 27.Aug.2019) TCDAT5 Tropical Storm Dorian Discussion Number 15 NWS National Hurricane Center Miami FL AL052019 1100 PM AST Tue Aug 27 2019 Reports from an Air Force Hurricane Hunter aircraft indicate that Dorian is yet to strengthen, and the initial intensity remains near 45 kt. The storm`s cloud pattern remains rather ragged-looking with no clear convective banding features. Since the storm has strong upper-level outflow over the western semicircle of the circulation and vertical shear should remain low for the next day or two, strengthening is still forecast before Dorian reaches Puerto Rico on Wednesday. Some weakening is likely by 24 hours due to the interaction of the circulation with Puerto Rico. The intensity forecast in 3-5 days remains problematic because of a significant spread in the model guidance and some run-to-run inconsistencies. The official intensity forecast has been increased in comparison to the previous ones. However, it is now near the low end of the numerical guidance suite. Dorian has turned toward the northwest, and the initial motion estimate is 310/11 kt. Over the next couple of days, the cyclone will be headed toward a weakness in the subtropical ridge. In 3-4 days, the global models show the ridge rebuilding somewhat over the western Atlantic. This scenario should cause Dorian to turn toward the left later in the forecast period. The official forecast has been shifted to the north of the previous one. This is in close agreement with the ECMWF model track, but south and southwest of the latest simple and corrected consensus predictions. Key Messages: 1. Tropical storm conditions are expected in the U.S. and British Virgin Islands and Puerto Rico on Wednesday, and are possible in portions of the Dominican Republic Wednesday night and Thursday. Hurricane conditions are possible in Puerto Rico on Wednesday. 2. Heavy rainfall over portions of Puerto Rico and the Dominican Republic could produce flash flooding during the next few days. Heavy rains are expected to occur over portions of the Bahamas and Florida later this week and into early next week. 3. The threat of tropical storm or hurricane conditions, along with storm surge, in the Bahamas and along portions of the Florida east coast have increased. Residents in these areas should monitor the progress of Dorian and ensure that they have their hurricane plan in place. 4. Uncertainty in the intensity forecast later this week remains higher than usual due a large spread in model guidance. storm. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 16.0N 63.0W 45 KT 50 MPH 12H 28/1200Z 17.0N 64.5W 55 KT 65 MPH 24H 29/0000Z 18.5N 66.5W 45 KT 50 MPH...INLAND 36H 29/1200Z 20.3N 68.1W 50 KT 60 MPH 48H 30/0000Z 22.1N 69.6W 55 KT 65 MPH 72H 31/0000Z 25.3N 72.7W 65 KT 75 MPH 96H 01/0000Z 27.4N 76.8W 70 KT 80 MPH 120H 02/0000Z 28.8N 81.0W 65 KT 75 MPH...INLAND $$ Forecaster Pasch |