Dorian Will Hit Florida As Category 2 Hurricane, New Forecast Says

Updated at 11:15 a.m. ET

Tropical Storm Dorian is poised to become a hurricane as it bears down on Puerto Rico and the Virgin Islands, bringing heavy rain and sustained winds up to 70 mph. Forecasters are now warning the storm will strengthen into a dangerous hurricane as it nears the U.S. mainland.

Puerto Rico, Vieques and U.S. Virgin Islands are now under alert, with hurricane conditions expected as the storm passes through that area later Wednesday. Dorian is currently some 25 miles southeast of St. Croix, the National Hurricane Center says in its 11 a.m. ET update on the storm.

Dorian will likely strengthen somewhat as it approaches Puerto Rico. And while it could lose some intensity by passing over that land mass, the storm is then expected to gain power. Within four days, its winds could top 115 mph, the National Hurricane Center says.

"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 NHC says.

The center's current predictions show Dorian hitting Florida's coast as a hurricane late Sunday or early Monday. It's expected to briefly become a major hurricane (Category 3 and above) before weakening somewhat into a Category 2, with winds of 100 mph.

While early forecasts showed the storm making landfall south of an area that's level with Orlando, more recent projections suggest it could arrive farther north.

Forecasters are warning of the potential for life-threatening flash floods in the storm's path. Southern and eastern portions of Puerto Rico and the Virgin Islands could see 4-6 inches of rainfall, with 10 inches possible in isolated areas. When the storm reaches Florida, it's expected to drop 4-8 inches of rain, with 10 inches in some spots.

Citing data collected from Air Force Hurricane Hunters and other sources, the NHC says, "Dorian remains a compact and asymmetric tropical storm." But that could change; the center says some projection models show Dorian "increasing in size by the time it nears the southeast U.S."

While Dorian's wind speeds have only grown by 10 mph since Monday, it's now projecting tropical storm-force winds outward up to 80 miles from the center — up from 45 miles on Monday and Tuesday.

By 9:30 a.m. ET, Dorian's outer bands were beginning to move over eastern Puerto Rico, according to the National Weather Service office in San Juan.

To prepare for rough conditions at sea, the Coast Guard captain in San Juan set "Port Condition ZULU" Wednesday for all ports in the U.S. Virgin Islands and Puerto Rico, shutting down all commercial traffic until the storm has passed and the facilities have been assessed.

Late Tuesday, President Trump declared an emergency in the commonwealth of Puerto Rico, ordering the Federal Emergency Management Agency to provide "equipment and resources necessary to alleviate the impacts of the emergency."

Puerto Rico Gov. Wanda Vázquez Garced thanked Trump for approving the declaration, saying it would "allow federal aid to arrive more quickly" after the tropical storm passes.

As it announced an increased threat of hurricane conditions on Florida's east coast, the hurricane center also noted that its forecasts are "on the lower end of the guidance envelope" — meaning it could raise more dire warnings as the storm continues to develop. [Copyright 2019 NPR]