Cayena, French Guiana

Weather Underground Forecast for Tuesday, May 21, 2013.

Expect little change in weather across the Gulf of Mexico on Tuesday high pressure ridging continues across the region. The ridge of high pressure will extend from the western Atlantic Ocean to the Texas coast, leading to continued southeasterly winds across the gulf. A few light isolated showers may develop in the southeastern gulf through Tuesday night.

Meanwhile, high pressure north of the Caribbean Sea and low pressure crossing the northern tier South America will maintain moderate to fresh trades across the Caribbean basin. Upper level energy streaming across the islands just north of the basin will kick up scattered showers and chances of thunderstorms in the Bahamas, Cuba, Hispaniola, and Puerto Rico. More robust showers and thunderstorms are anticipated in the southwestern corner of the basin and across Panama and Costa Rica due to the proximity of the monsoon trough.

Elsewhere, the remnants of Alvin will continue on a westward track through the eastern Pacific Ocean on Tuesday. This system has a low chance, 10 percent, of becoming a tropical cyclone again on Tuesday.

For South America, heavy rain, strong winds, and storms will continue across the northern tier of the continent as warm and humid flow streams across the region with a tropical wave of low pressure. To the south, a trough of low pressure will support widely scattered light showers from north-central Argentina through southeastern Paraguay into southeastern Brazil. Further south, light to moderate precipitation continues in Chile as a frontal boundary with waves of low pressure continue to impact the country.