Tropical Wave No. 19 is crossing Costa Rica today, increasing the chance of rain, thunderstorms and strong wind gusts across much of the country, according to the National Meteorological Institute (IMN). The strongest effects are expected in the Caribbean, the Northern Zone, the Central Valley, northern Guanacaste and mountain areas. Weather officials forecast frequent gusts of 70 to 85 km/h in several parts of the country, with possible gusts above 95 km/h in some sectors.
The forecast carries risks as heavy rain over saturated ground can quickly lead to ponding, swollen streams, falling branches and poor visibility on mountain roads. Anyone traveling by road or air today should allow extra time, check local conditions before departure and avoid crossing flooded streets or rivers.
Rain and thunderstorms were expected to begin early this morning in the Caribbean and Northern Zone. The IMN said some watersheds in those regions already have saturated soils, making them more vulnerable to additional rainfall.
Strong trade winds may also push rain from the mountains into lower-lying areas of the Central Valley and Guanacaste. In the Central Valley, partly cloudy skies are expected through much of the day, with periods of drizzle or rain, especially near mountain zones during the afternoon. San José is forecast to range from about 19.9°C (68°F) to 25.6°C (78°F).
The Northern Pacific is expected to see mostly sunny to partly cloudy skies, but windy conditions will continue throughout the day. Light rain is possible in mountainous areas. Nicoya is forecast to be one of the warmer points in the country, with temperatures between 22.6°C (73°F) and 36.8°C (98°F).
In the Central Pacific, morning skies should remain partly cloudy before cloud cover increases in the afternoon. Thunderstorms are expected to develop later in the day, with rain continuing into the night. Parrita is forecast to range from 18.5°C (65°F) to 32.8°C (91°F).
The South Pacific will follow a similar pattern, with partly cloudy skies early, stronger cloud buildup in the afternoon, thunderstorms and rain lingering into the night. Golfito is forecast to range from 21.1°C (70°F) to 29°C (84°F).
In the Northern Caribbean, rain is expected from the early morning, with showers and the possibility of isolated thunderstorms through the morning. Isolated showers may continue during the afternoon before rain picks up again overnight. Guápiles is forecast between 23.6°C (74°F) and 28.3°C (83°F).
The Southern Caribbean is also expected to see rain and showers from early morning, with possible isolated thunderstorms through the first half of the day. Conditions should ease somewhat in the afternoon before intensifying again overnight. Limón is forecast between 23°C (73°F) and 28.6°C (83°F).
Although the tropical wave is expected to move away from Costa Rica later today, unstable conditions may continue Friday as the system interacts with the Intertropical Convergence Zone, the broad band of humidity and storms that often fuels Costa Rica’s rainy-season downpours.
Those in areas prone to flooding or landslides should keep drainage areas clear, secure loose outdoor objects and monitor official updates. Drivers should use extra caution on mountain routes, coastal roads, and areas with poor drainage, especially during afternoon and nighttime rain.
