If you have plans outdoors today, get them done before lunch. Tropical Wave 47 is crossing Costa Rica today, and afternoon downpours with thunderstorms are expected across the Central Valley, the Pacific and the Northern Zone, according to the National Meteorological Institute (IMN).
The morning is your window so expect mostly fair to partly cloudy skies early, with only isolated showers along the Pacific and Caribbean coasts. Clouds build toward late morning, and the storms start between late morning and early afternoon. The heaviest rain is forecast along the central mountain range and across the north. That puts the mountain roads around the Central Valley and the routes into San Carlos and the Arenal area squarely in the path.
The north already got a preview yesterday as heavy afternoon rain sent water into homes, businesses and the technical high school in Aguas Zarcas, according to local reports, and covered part of the road in La Marina de La Palmera. The National Emergency Commission (CNE) said yesterday afternoon it had no official reports of damage.
The storms won’t stop at sunset. Early tonight, downpours with possible thunderstorms are forecast for the Central and South Pacific and the Northern Zone, with scattered rain in the Central Valley and the North Pacific. Patches of fog are possible in the Central Valley overnight.
Temperatures stay warm ahead of the rain. San José ranges from 18.8°C (66°F) to 28.3°C (83°F). Liberia is the hot spot at up to 36.1°C (97°F), while Quepos tops out near 31.2°C (88°F) and Ciudad Quesada near 28°C (82°F).
The unsettled weather could carry into Sunday afternoon. Once the wave moves on, the IMN expects slightly less rain on the Pacific side from early next week. The Caribbean coast and plains should see less frequent rain than the rest of Costa Rica this weekend. If you’re driving, aim to be off mountain roads by early afternoon. Rain on ground that is already wet can swell streams and loosen slopes quickly, and visibility drops fast in a heavy downpour. Don’t try to cross a flooded road or river, because water that looks shallow can still sweep a car away.
If you’re hiking, rafting or at the beach, the same timing applies. Lightning is the main danger with these afternoon storms, so head for shelter as soon as you hear thunder and get out of the water. Rivers can also rise fast after rain upstream, even where the sky above you is still dry.
Tropical waves cross Costa Rica regularly during the rainy season, and this is the 47th of the year. Keep an eye on the IMN’s afternoon updates and call 911 to report an emergency.
