Tropical Storm Bret bears down on Caribbean islands, second storm developing behind

Tropical Storm Bret and Tropical Depression Four on satellite imagery courtesy of NASA. Bret is the larger storm on the left and Four is the smaller storm on the right.

Tropical Storm Bret continues as a strong tropical storm with maximum sustained winds near 110 km/h, just shy of category one hurricane strength.

The storm will move across the Lesser Antilles, a group of islands on the eastern Caribbean Sea, Thursday evening.

St. Lucia is under both a tropical storm warning and a hurricane watch. A tropical storm warning is in effect for Martinique and Dominica and tropical storm watches extend to Barbados and St. Vincent.

Bret threatens parts of the islands with rain that could range 75 to 200 mm. Tropical storm force winds are a risk for those island under the warnings. Dangerous surf and rip tides are also expected upon and following the storms passage.

After passing through the island group, Bret is forecast to continue moving westward into the Caribbean Sea as a tropical storm on Friday.

Tropical Storm Bret is forecast to cross the Lesser Antilles on Thursday evening.

To the east of Bret, Tropical Depression Four has developed.

The storm is forecast to continue to strengthen while moving northwestward into Friday. Once it reaches tropical storm strength it will be named Cindy. The system is forecast to move to a position east of the Bahamas by early next week as a tropical storm or tropical depression.

There is no imminent risk from either storm to the Maritimes or Atlantic Canada. The more northerly movement of Tropical Depression Four does mean we may need to watch the remnants of that system closely next week.

Tropical Depression Four is likely to become Tropical Storm Cindy. The storm taking a northwestward path that will place it east of the Bahamas early next week.

The start of hurricane season has been unusually active in the tropical Atlantic. That area typically has more frequent development later in the season in late summer and early fall. A contributing factor is unusually warm Atlantic Ocean waters, much of the southern Atlantic is currently sitting one to three degrees above average.

The presence of these warmer waters and the favourable conditions they create for tropical storms and hurricanes was noted in the forecast for the hurricane season this year.

Sea surface temperature anomaly courtesy of the National Atmospheric and Oceanic Administration. Much of the Atlantic is anomalously warm.