Weather Warning

Intertropical Convergence Zone and regional instability over the country this Monday

Jun 09, 2025

10:30 a.m.

Diagnosis: A broad region of instability is occurring in central and southern Central America, due to factors such as the active Intertropical Convergence Zone, instability in the regional upper atmosphere, and moisture incursions from the Caribbean due to the presence of accelerated trade winds in that basin. During the morning, showers have occurred in parts of the Northern Caribbean and northern parts of the Northern Zone, with accumulated rainfall between 0.5 and 25 mm in the last 6 hours.

Forecast: Variable rainfall is expected throughout the morning in low-lying areas of the Northern Zone, the Northern Caribbean, and parts of the Southern Caribbean, with accumulated rainfall between 10 and 40 mm, with maximums of up to 60 mm during the 6-hour periods. In the early afternoon, cloudy conditions are possible in the mountains of these parts of the Caribbean, with accumulated rainfall between 20 and 40 mm, and more locally, up to 80 mm.

In the case of the Central and South Pacific, showers accompanied by thunderstorms are expected in the afternoon and evening. The heaviest rainfall is expected in mountainous areas of the South Pacific, coastal areas, and the surrounding Gulf of Dulce, along with the surrounding mountains and the coasts of the Central Pacific. Accumulated rainfall over the past 12 hours is expected to range between 25 and 50 mm, with peak rainfall between 70 and 90 mm. The Central Valley will experience rain in eastern and northern areas with scattered showers and a possible thunderstorm to the west. Accumulated rainfall is expected to range between 10 and 50 mm.

The National Meteorological Agency (IMN) continues to monitor the possible development of a low-pressure system from this active convergence zone in the Pacific near the country, which would increase the possibility of rain for this area in the second half of this week. Stay tuned for further updates.

Warning: Currently, soil saturation rates between 85% and 95% are recorded around the canton of Osa, the mountains of the South Pacific, Central Pacific, and the Nicoya Peninsula, as well as the mountains of the Northern Zone and the surrounding areas of Sarapiquí and Braulio Carrillo, increasing vulnerability to incidents.

Due to the above, the IMN recommends:

• Caution due to sewer saturation in areas prone to this type of flooding.

• Prepare for thunderstorms and seek shelter in a safe place if strong wind gusts occur or are felt 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

Jose Valverde Mora

Meteorologist

DMSA-IMN

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