Weather Warning (Update)

Instability after the passage of Tropical Wave #1

May 14, 2025

04.35 p.m.

Discussion: Atmospheric instability persists over Costa Rica following the passage of Tropical Wave #1 yesterday. This, along with activity associated with the Intertropical Convergence Zone (ITCZ) and daytime warming, has generated heavy rains and thunderstorms this afternoon, particularly in the Pacific, Northern, and Caribbean regions. Rainfall amounts ranged from 15 mm to 50 mm over a 6-hour period, with the highest accumulations in a 3-hour period recorded in Río Nuevo de Pérez Zeledón with a maximum of 142 mm, followed by Laurel de Corredores with 83 mm.

Forecast: Rain and thunderstorms will continue throughout the Pacific during the remainder of the afternoon and early evening. Rainfall and thunderstorms are expected to fall between 30 mm and 70 mm over a few hours, with possible higher amounts at specific times. These rains could reach the coast later in the evening.

In the Central Valley, scattered rains may occur in the late afternoon and early evening, with accumulated rainfall of between 15 mm and 40 mm over a six-hour period. The possibility of fog banks cannot be ruled out. In the Northern Zone and the Caribbean, scattered showers will continue, with estimated accumulated rainfall of between 10 mm and 50 mm over a six-hour period.

Warning: Soil saturation is high in the South and Central Pacific, the Sarapiquí Basin, the western part of the Central Valley, and the General Valley. Attention is due to the presence of a strong storm, where intense rain in short periods, lightning strikes, and downpours are common in these events.

Because of the above, the IMN recommends:

• Be cautious about sewer saturation in areas prone to this type of flooding.
• Prevent yourself from 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

Rebeca Morera R
Meteorologist
DMSA-IMN