|
Show Selection: |
| #979436 (Received by flhurricane at: 10:42 PM 25.Aug.2019) TCDAT5 Tropical Storm Dorian Discussion Number 7 NWS National Hurricane Center Miami FL AL052019 1100 PM AST Sun Aug 25 2019 Dorian`s cloud pattern hasn`t changed much since this afternoon, with deep convection oscillating up and down. There are few banding features evident, and the upper-level outflow is somewhat restricted over the eastern semicircle of the circulation. The intensity estimate remains at 45 kt and is in agreement with a recent Dvorak estimate from TAFB. The intensity forecast for this storm is a challenge, since the numerical guidance depicts a wide range of possibilities. The GFS and ECMWF global models dissipate Dorian over the Caribbean in about 4 days, probably due to the hostile environment associated with an upper-level low near Hispaniola. Another unfavorable factor could be dry air that is also forecast by the global models over the Caribbean. On the other hand, the statistical/dynamical models DSHIPS and LGEM do not weaken the system until it interacts with the land mass of Hispaniola. The official forecast is close to the intensity model consensus, IVCN, but it should be noted that there is greater than usual uncertainty associated with this forecast. The motion continues to be slightly north of due west or 280/12. Dorian is moving along the southern side of the subtropical ridge. The track models are in good agreement that the cyclone will gradually turn toward the west-northwest on Monday. A slight weakness in the ridge near 70W longitude in a couple of days should induce a gradual turn to the northwest later in the forecast period. The official track forecast is close to the corrected consensus, HCCA prediction and is also very close to the previous NHC track. Key Messages: 1. Dorian is expected to bring tropical storm conditions to portions of the Lesser Antilles, where tropical storm watches and warnings are in effect. Residents in these areas should refer to advice from local government officials and products from their local meteorological service for additional information. 2. Dorian is expected to produce 2 to 4 inches of rainfall across portions of the Lesser Antilles, with isolated amounts as high as 6 inches. 3. While it is too soon to determine the specific time or magnitude of possible direct impacts in Puerto Rico, the Virgin Islands, or Hispaniola interests in those areas should monitor the progress of Dorian. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 11.7N 55.3W 45 KT 50 MPH 12H 26/1200Z 12.1N 57.0W 50 KT 60 MPH 24H 27/0000Z 12.8N 59.3W 55 KT 65 MPH 36H 27/1200Z 13.7N 61.5W 55 KT 65 MPH 48H 28/0000Z 14.8N 63.6W 60 KT 70 MPH 72H 29/0000Z 17.2N 67.6W 65 KT 75 MPH 96H 30/0000Z 19.5N 71.0W 40 KT 45 MPH...INLAND 120H 31/0000Z 21.5N 74.0W 25 KT 30 MPH...OVER WATER $$ Forecaster Pasch/Latto |