Weather Underground Forecast for Monday, May 20, 2013.

In the Eastern Pacific Basin, an area of low pressure associated with the remnants of Tropical Storm Alvin has a medium, 30% chance of becoming a tropical cyclone again by Monday. The system remains about 950 miles west-southwest of Manzanillo, Mexico and continues to producing shower and thunderstorm activity. Conditions are favorable for development, thus, the system will remain under close watch for signs of further development. In the Atlantic Basin however, tropical cyclone activity is not anticipated on Monday. In the south, a tropical wave moves into Venezuela from the tropical Atlantic Ocean, bringing moderate to heavy showers and thunderstorms that may reach northward into the Lesser Antilles. To the west, an area of low pressure lingers over the southwestern Caribbean Sea and supports shower and thunderstorm activity over Panama and Costa Rica. In the north, a trough of low pressure over Mexico will maintain chances of showers and thunderstorms across central and eastern Mexico. Mexico City will see partly cloudy skies with a afternoon thunderstorms and highs in the lower 80s(F)/ upper 20s(C).

In South America, the tropical wave of low pressure moving into Venezuela will kick up some heavy rainfall, strong winds, and thunderstorm development. In the west, onshore flow from the Pacific Ocean maintains showers and thunderstorms across Colombia, Ecuador, and northern Peru as well. To the south, a low pressure system over southern Brazil finally advances eastward and offshore, pulling wet weather eastward with it. A front over the southern tip of the continent maintains heavy precipitation and gusty winds for far southern Chile and Argentina.

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