SAN JOSÉ, COSTA RICA — Atmospheric conditions across Costa Rica are set to deteriorate significantly starting Saturday afternoon as Tropical Wave No. 43 enters national territory, according to an official bulletin from the National Meteorological Institute (IMN).
Currently positioned over western Panama, the tropical wave is advancing directly into a highly active Intertropical Convergence Zone combined with high atmospheric moisture. This combination will generate intense atmospheric instability, severe weather, and continuous rainfall expected to last through early next week.
Regional Breakdown & Expected Rainfall
While instability will affect most of the country, the highest precipitation volumes will target the Caribbean slope and the Northern Zone, with potential overflow toward the Central Valley.
| Region | Expected Rainfall | Peak Accumulations | Key Risks |
| Caribbean & Northern Zone | 30 – 60 mm | Up to 90 mm | Soil saturation, swollen rivers, flash floods |
| Pacific Coast (Slope) | 20 – 40 mm | Up to 80 mm | Coastal storms, urban flooding |
| Mountainous & Pass Areas | Variable | High intensity | Landslides, fallen trees, strong wind gusts |
High-Risk Zones Requiring Maximum Precaution
The IMN emphasizes heightened vigilance for specific sectors where soils are already moderately to highly saturated from recent precipitation:
- Northern Caribbean Basin
- Eastern Northern Zone
- South Pacific Region
In these locations, additional rainfall will rapidly increase the likelihood of flash floods, sewer overflows, and landslides near hillsides and riverbanks.
Gale-Force Wind Gusts and Maritime Warnings
Heavy rainfall is not the only hazard associated with this system. Accelerated trade winds in the Caribbean Sea basin will bring wind speeds of 40 to 60 km/h near mountain passes. Furthermore, isolated downdrafts during severe thunderstorms could trigger maximum gusts reaching up to 80 km/h.
These intense gusts pose severe risks of falling branches, trees, power lines, and billboards. Extreme caution is urged in Guanacaste, national parks, and volcanic zones.
ALERT — Maritime & Aviation Safety: Rough seas are expected along the Pacific slope. Small craft navigation should exercise extreme caution in the North Pacific, Gulf of Nicoya, and Northern Central Pacific. Aviation operators are also warned of severe localized air turbulence near storm cells.
Official Safety Recommendations
Seek Safe Shelter: Move indoors immediately during active lightning storms or sudden wind gusts.
Avoid Dangerous Crossings: Do not attempt to cross flooded roads, streams, or swollen rivers.
Secure Loose Objects: Secure outdoor items that could become dangerous projectiles in 80 km/h winds.
Stay Updated: Monitor official IMN updates and emergency broadcasts via local authorities.
