Subseasonal forecast

Valid from  december 16-January 12 , 2024

(4 weeks)

General comment:

Moderate winds will continue in the majority of the country for the second half of the month, favoring very rainy conditions in the Caribbean and northern mountainous zone. Like this, isolated rains are expected in the mountains to the north and east of the Central Valley.

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

 

1.Forecast from  december 16-22, 2024

This week, the establishment of the dry season is expected in the North Pacific, Central Pacific and Central Valley. However, normal rainfall will occur in the Central Pacific, South Central Valley and South Caribbean (accumulations between 20-70 mm per week in the Caribbean and greater than 100 mm in the Pacific). In the North Pacific, Guatuso-Los Chiles, above-normal rainfall will occur, despite the establishment of the dry season this week (accumulations greater than 60 mm per week).

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

2.Forecast from  december 23-29, 2024

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  december 30-January 5, 2024

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  january 6-12, 2024

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 december 16-22, 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