The first tropical storm of this year's Atlantic hurricane season has formed in the Caribbean.

U.S. weather forecasters say Tropical Storm Arlene developed Thursday, triggering heavy rain and squalls across the Cayman Islands and western Cuba.  A tropical storm warning was in effect for western Cuba from Pinar del Rio to the Havana area.

At last report, Arlene was 180 kilometers south-southeast of Cuba's western tip, moving to the north at 13 kilometers per hour, with winds at 65 kilometers per hour.

Forecasters say parts of Florida, especially the Keys, could get heavy rain from the storm.

The Atlantic hurricane season runs from June 1 through November 30.  Last year, four hurricanes struck Florida. 

Some information for this report provided by AP and Reuters