Subseasonal forecast

Valid from  March 17-april 13 , 2025

(4 weeks)

General comment:

The last two weeks of March will see very little rainfall in the country compared to normal in the Caribbean, while the Pacific will continue to be much wetter (despite dry season conditions). On the other hand, there will be very few cold snaps. Although March and April are warm, most of the country is expected to remain warmer than normal, especially in the Caribbean and the Northern Zone. The Zenith Sun (perpendicular rays over the country) is expected to be present during the week of April 9-13.

Fig. 1. Weekly precipitation forecast by region for the next 4 weeks.

 

1.Forecast from  March 17-23, 2025

This week, normal rainfall will occur in most of the country, meaning that the dry season will continue in the Pacific and Northern Zone with little rainfall. On the other hand, in the Caribbean, normal rainfall will occur with amounts between 20-50 mm accumulated during the week (weekly accumulations less than 30 mm in the Pacific and Central Valley). High daytime temperatures are expected throughout the country.

Probability of extreme: low (around 20%)
Forecast uncertainty: low

2.Forecast from  March 24-30, 2025

This week there will be a decrease in rainfall in the South Caribbean; most of the country will have very little rainfall, except for the Guatuso Zone, which will have more rain than normal, as well as the North Pacific (accumulated between 20-50 mm per week in the Caribbean and 50-90 mm in the Pacific).

Probability of extreme event:  low (around 20%)
Prognosis uncertainty: medium

3. Forecast from  March 31-april 6, 2025

This week, normal rainfall will continue throughout the Caribbean and the Northern Zone (accumulated between 20-60 mm per week in the Caribbean and more than 120 mm in the Pacific). In the Pacific, the last days of October and the beginning of November will see slightly above-normal rainfall (over 150 mm per week).

 

Probability of extreme event: low (around 30%)
Prognosis uncertainty: medium

4. Forecast from  april 7-13, 2025

Very weak trade winds and the presence of the Intertropical Convergence Zone over the country. The Intertropical Convergence Zone is expected to favor rainy conditions throughout the Pacific and Central Valley.

Probability of extreme event: low (around 20%)
Prognosis uncertainty: high

 

Forecast of extreme events from March 17-23, 2024

Moderate floods and frontal systems continue around the region, which makes the rainy conditions in the Pacific region unfavorable. Although there will be rainy conditions in the Caribbean these will be normal for the season.

Fig. 2. Forecast of extreme events for the next 2 weeks (training areas).

 

 

Forecaster: Daniel Poleo
Maps: Nury Sanabria Valverde
Unidad de aplicaciones climáticas
Departamento de Desarrollo/IMN