Tropical Storm Dorian's center has reformed and is expected to continue strengthening as it moves through the eastern Caribbean Sea, according to the National Hurricane Center.
As of the NHC's 2 p.m. ET advisory on Tuesday, Dorian's center was located about 70 miles west-northwest of Martinique. The storm, which has maximum sustained winds of 50 mph, is moving west-northwest at a speed of 13 mph.
"Data from an Air Force Reserve reconnaissance aircraft and the Martinique radar indicate that the center of Tropical Storm Dorian has reformed farther north," the NHC said in a statement.
A hurricane watch is in effect for Puerto Rico and Dominican Republic from Isla Saona to Samaná, where a tropical storm warning is also currently in effect.
A tropical storm watch is in effect for Saba, St. Eustatius and parts of the Dominican Republic.
The center of Dorian will move across the eastern and northeastern Caribbean Sea, passing near or south of Puerto Rico on Wednesday – moving near or over eastern Hispaniola Wednesday night, according to the NHC.
In Puerto Rico and the Dominican Republic, from 4 inches to 6 inches of rain is expected – with isolated rainfall of 8 inches. The rainfall may cause life-threatening flash floods.
"Tropical storm conditions are expected and hurricane conditions are possible in Puerto Rico on Wednesday and in portions of the Dominican Republic late Wednesday and Thursday," the NHC added.
As concern grows in Puerto Rico due to Dorian's forecast strengthening, President Donald Trump on Twitter reiterated, as he has in the past, his false claim that Congress approved $92 billion for the commonwealth after Hurricane Maria.
Congress allocated $42.5 billion to disaster relief for Puerto Rico, according to federal data, but the island had received less than $14 billion through May. Maria caused an estimated $90 billion in damage on the island.