By late Tuesday morning, the storm was located about 60 miles (95 km) west-northwest of St. Lucia, blowing maximum sustained winds of 50 miles per hour, according to the NHC.
Forecast models show Dorian could have maximum sustained winds as high as 130 miles per hour (209 kph) as it approaches the Florida coast over the Labor Day weekend, putting it right at the threshold of Category 4 strength. Rain will be a big issue for the island, says FOX 13's meteorologist Dave Osterberg.
Tropical Storm Dorian has strengthened overnight as it steadily approaches Puerto Rico and the Virgin Islands.
The NHC's "cone of uncertainty" forecast shows that the storm or its remnants will affect Florida as of Sunday morning at around 8 a.m.
Heavy rains are expected to hit over portions of Florida and other portions of the southeastern USA later this week and early into next week.
Dorian caused an islandwide blackout in St. Thomas and St. John in the U.S. Virgin Islands, and scattered power outages in St. Croix, government spokesman Richard Motta said.
All of the models show Dorian strengthening again soon over warm waters.
Also on Monday, a new tropical depression formed between the USA eastern coast and Bermuda. Coastal areas of the Southeast could see four to eight inches of rain, with some isolated areas getting ten inches.
It's possible that Dorian may impact Florida, but it is too early to say in what ways it may do so.
Dorian has now been upgraded to a hurricane with maximum sustained winds near 75 miles per hour.
The NHC highlighted the threat of the tropical storm in the Bahamas and along parts of the Florida's east coast increased. These factors all suggest Dorian will become a hurricane on its approach.
A tropical storm watch has been discontinued for Grenada and its dependencies. The storm has dumped up to 10 inches of rain on some Caribbean islands.