je.st
news
Tropical Storm Dorian Forecast Discussion Number 4
2019-08-25 10:49:52| National Hurricane Center (Atlantic)
Issued at 500 AM AST Sun Aug 25 2019 000 WTNT45 KNHC 250849 TCDAT5 Tropical Storm Dorian Discussion Number 4 NWS National Hurricane Center Miami FL AL052019 500 AM AST Sun Aug 25 2019 The convective organization of Dorian is about the same as it was several hour ago with the storm only producing small, generally short-lived thunderstorm areas. GOES-16 1-minute satellite images have been particularly helpful in locating the center in between bands of convection to the north and south of the cyclone. The initial wind speed is kept at 35 kt based on the most recent TAFB Dvorak fix. Dorian continues moving westward or 280/11 kt. A west to west-northwestward course of the tropical cyclone is expected during the next several days as a mid-level ridge remains in place over the southwestern Atlantic Ocean. There has been a noticeable change in the guidance tonight, with many models faster and to the southwest of earlier runs. This is not uncommon in the early stages of tropical Atlantic cyclones where the guidance has historically demonstrated a slow, poleward bias. Given the lack of interaction with even features at the subtropical latitudes, it makes sense to follow the trend of the latest guidance and shift the track about 30 n mi southwest during most of the forecast. Notably, the GFS and ECMWF models are still south of the new NHC prediction, and further adjustments could be required later today. The intensity forecast appears to be a battle between an increasingly conducive oceanic and shear environment during the next couple of days versus plentiful dry air in the mid-levels of the atmosphere. These mixed conditions primarily point toward slow strengthening during that time while Dorian approaches the Windward Islands, and no change has been made to the first part of the forecast. While Dorian still has a chance to become a hurricane over the eastern Caribbean, model guidance has been trending toward a higher-shear environment caused by a large upper low in a few days. Thus the intensity forecast is reduced from the previous one at long range, although it remains above most of the guidance. It should be stressed that Dorian is likely to be a difficult cyclone to forecast due to the marginal environment it is embedded within and its small size. Key Messages: 1. A Tropical Storm Watch has been issued for Barbados, and additional watches and warnings for the Windward and Leeward Islands will likely be required later today. 2. It is too soon to determine the specific timing or magnitude of impacts in Puerto Rico or Hispaniola, but interests in those areas should monitor the progress of Dorian. FORECAST POSITIONS AND MAX WINDS INIT 25/0900Z 11.0N 51.6W 35 KT 40 MPH 12H 25/1800Z 11.3N 53.3W 40 KT 45 MPH 24H 26/0600Z 11.8N 55.5W 45 KT 50 MPH 36H 26/1800Z 12.4N 57.7W 50 KT 60 MPH 48H 27/0600Z 13.2N 59.9W 55 KT 65 MPH 72H 28/0600Z 15.2N 63.9W 65 KT 75 MPH 96H 29/0600Z 17.1N 67.6W 60 KT 70 MPH 120H 30/0600Z 19.5N 71.0W 35 KT 40 MPH...INLAND $$ Forecaster Blake
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||