Tropical Storm Bret is making its way toward various eastern Caribbean islands : NPR

Tropical Storm Bret is moving west across the Atlantic and could become a threat to eastern Caribbean islands, according to the National Hurricane Center.

As of about 11 a.m. Atlantic Standard Time on Tuesday, Bret was about 945 miles east of the Windward Islands, a group of Caribbean islands that are part of the Lesser Antilles and include Grenada, Dominica, Martinique, St. Lucia and St. Vincent and the Grenadines.

The storm is moving at 21 mph, with maximum wind speeds of 40 mph, according to the National Hurricane Center.

Currently no tropical storm watches or warnings are in effect, but they could come later into Tuesday for parts of the Lesser Antilles. The National Hurricane Center said people living on those islands, as well as in Puerto Rico and the Virgin Islands, should closely follow updates.

Four to 10 inches of rain are possible from Guadeloupe to St. Lucia, while 2 to 4 inches are possible across Barbados and St. Vincent and the Grenadines. The rain could cause flash flooding and isolated urban flooding, the National Hurricane Center said.