Weather Underground Forecast for Sunday, May 19, 2013.

Tropical cyclone activity is not anticipated for the Atlantic Basin or the Eastern Pacific Basin on Sunday. However, areas of active weather will persist for the Caribbean Sea and Latin America. Low pressure continues moving through the Southern U.S., pushing a trough of low pressure across Mexico and into the Gulf of Mexico. This will continue pulling moisture onshore from the east, maintaining chances of showers and thunderstorms across central and eastern Mexico. Mexico City will see partly cloudy skies with a chance of thunderstorms in the afternoon and evening. To the south, a monsoonal trough of low pressure lingering over Central America will allow for onshore flow from the Pacific Ocean to prevail. This will support more thunderstorm activity across Panama and Costa Rica. To the east, a tropical wave of low pressure approaches Venezuela from the east, bringing storms to the region. However, these storms will remain south of the Greater and Lesser Antilles on Sunday.

In South America, onshore flow from both the Atlantic and Pacific will maintain warm and moist conditions over the northern countries, supporting moderate to heavy showers and thunderstorms. To the south, a small area of low pressure moves eastward and away from southern Brazil, but allows for a few showers to persist from Santa Catarina through Rio de Janeiro. Further south, a front approaches the southern tip of the continent, bringing heavy rains and strong winds to the region.