The country today continues to be under the influence of one of those tropical waves, a trough of low pressure that brings rain, thunderstorms and weather instability.
The Instituto Meteorológico Nacional said that there will be rain today, mainly in the Pacific and the northern zone. There also will be some in the Central Valley. The agency urged caution.
There was some rain Thursday afternoon and evening in the Central Valley.
The weather institute said there would be heavy downpours with strong winds.
The tropical wave is to the north along the Caribbean coast of Nicaragua and Honduras. But the effects are being felt here.
The wave also seems to be pulling what is known as the zone of tropical convergence north to amplify the rain here.
The weather institute issued a prediction of up to 100 millimeters of rain for the northern zone, the Pacific and the Central Valley at 3:30 p.m. Thursday.
But by early today, only 13.6 millimeters (less than half an inch) had fallen in San José and just 20.8 millimeters (eight-tenths of an inch) had been reported at Daniel Oduber airport in Liberia. The total of 100 millimeters is about four inches.
There was heavy rain elsewhere. The Consejo Nacional de Vialidad said that a storm on the Interamericana Ruta 1 at Cambronero caused trees to fall blocking the important route. The route was believed to have been opened later Thursday evening.
The Instituto Meteorológico Nacional said that the rain would intensify though this morning and that the unstable weather would continue into Saturday.