We’ll have to keep our eyes on Tropical Storm Dorian over the next several days as the NHC is now forecasting it to become a major hurricane before making it to the east coast of Florida on Monday morning. Any jog in the forecast track could bring some of the effects from Dorian over parts of Central Alabama next week. Here is the latest discussion from the NHC:
Satellite and radar images indicate that the cloud pattern has become better organized during the past several hours. This was confirmed by data from an Air Force reconnaissance plane currently investigating Dorian, which reported a flight-level wind of 72 kt and a peak SFMR value of 60 kt. The estimated central pressure was 999 mb in the last fix. On this basis, the initial intensity has been adjusted upward to 60 kt. Only a slow strengthening is anticipated today while Dorian is moving through the U.S. and British Virgin Islands. However, once the cyclone reaches the western Atlantic well east of the Bahamas, it will encounter a favorable environment of low shear and warm waters, resulting in a more marked intensification. The NHC forcast is more aggressive than the previous one and brings Dorian to category 3 intensity by the end of the period. This forecast very closely follows the intensity consensus, the HCCA model, and the SHIPS guidance.
Fixes from the reconnaissance plane indicate that Dorian has been moving toward the northwest or 315 degrees at 11 kt. The cyclone is heading toward a weakness in the Atlantic subtropical ridge, and this motion should continue for the next 2 to 3 days. However, after that time, all global models build a robust ridge over the western Atlantic, and this flow pattern should force Dorian to turn more to the west-northwest toward Florida and the southeast coast of the United States. All indications are that by this Labor Day weekend, a powerful hurricane will be near the Florida or southeastern coast of the United States. The new NHC track forecast is not significantly different from the previous one, and it very closely follows the multi-model consensus TVCA and the HCCA. Users are reminded not to focus on the exact forecast track, as the average 5-day track error is around 200 miles.
1. Hurricane conditions are expected in the U.S. and British Virgin Islands, Culebra, and Vieques today. Tropical storm conditions are expected in Puerto Rico today with hurricane conditions possible.
2. Heavy rainfall over portions of Puerto Rico and the U.S. and British Virgin Islands could produce flash flooding during the next couple of days. Heavy rains are expected to occur over portions of the Bahamas, Florida, and elsewhere in the southeastern United States later this week and into early next week.
3. The risk of dangerous storm surge and hurricane-force winds is increasing in the central and northwestern Bahamas and along the Florida east coast, although it is too soon to determine where these hazards will occur. Residents in these areas should ensure that they have their hurricane plan in place and not focus on the exact forecast track of Dorian’s center.