Weather Warning (UPDATE)

Tropical Wave #1 crossing Costa Rica this Tuesday

13 de mayo de 2025

05.30 p.m.

Discussion: Tropical Wave 1 entered the country early this morning and, in conjunction with the Intertropical Convergence Zone, has generated very unstable atmospheric conditions across the country.

Over the last 12 hours, maximum rainfall has ranged between 20-40 mm in the Caribbean and Northern Zone, with a localized accumulation of 70 mm in Sarapiquí. Maximum rainfall has ranged between 5-20 mm in the Central Valley, and between 1-13 mm in the North Pacific. Maximum rainfall in the Central and South Pacific has ranged between 30-55 mm, with a localized accumulation of 90 mm in Río Nuevo de Pérez Zeledón.

In addition, landslides have been reported in Golfito (PS) and San Carlos (ZN), as well as flooding in Golfito and Pérez Zeledón. A strong downburst event was also reported in Cajón de Pérez Zeledón.

Forecast: By late this afternoon, rainfall activity has diminished across most of the country; however, several active convective cores remain.

The border area with Panama, the surrounding Gulf of Dulce and Osa Peninsula, and the coastal areas of the Central Pacific are particularly experiencing the most activity, and variable rainfall, including isolated showers with thunderstorms, is expected to continue for the next 2-4 hours.

The Caribbean and North Zone will experience mostly cloudy skies with scattered showers in the early evening. Showers with thunderstorms are expected for mountainous areas in the south and near the central coastline.

The Central Valley is expected to have partly to mostly cloudy skies with drizzle across most of the region for the next 1-3 hours. Localized showers are possible in mountainous areas to the west and north.

The tropical wave will be leaving the country during the course of Tuesday night. However, upon entering the Pacific Ocean, it will add instability to the low-pressure systems associated with the Intertropical Convergence Zone, causing rainfall in our country to continue increasing in the second half of the week.

Warning: Moderate/high soil saturation persists in the South Pacific and Central Pacific, the Sarapiquí Basin, the western part of the Central Valley, and the General Valley. Be aware of the presence of a strong storm, where intense rain in short periods, lightning strikes, and downbursts are present in these events.

Due to the above, the IMN recommends:

• Caution due to sewer saturation in areas prone to this type of flooding.
• Prepare for a thunderstorm and seek shelter in a safe place if strong wind gusts occur or are perceived near storm clouds, due to the possible fall of tree branches, power lines, among other things. These gusts can reach 80 km/h in some isolated cases.
• Stay informed through social media: Twitter: @IMNCR, Facebook: Instituto Meteorológico Nacional CR, and the website: www.imn.ac.cr

Roberto Vindas, DMSA-IMN Meteorologist

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