Weather Warning

Tropical wave #29

September 5, 2024

9.30 am

Diagnosis: OT#29 is positioned west of Panama, with its greatest instability beginning to enter the Gulf of Honduras. The United States National Hurricane Center maintains a 30% probability of becoming a tropical depression in the next 7 days when it reaches northern Central America or southern Mexico.

The passage of the wave and the proximity of the Intertropical Convergence Zone, together with local factors, will increase instability in the country this Thursday. This morning, light to moderate rains have been recorded on the Central Pacific coast, south of the Nicoya Peninsula, and the northern border sector.

Forecast: Tropical wave #29 will be passing through Costa Rica this afternoon and evening, reinforcing the afternoon rainfall towards the end of the afternoon today, Thursday, and during Friday in the Pacific and Northern Zone.

Specifically this Thursday, during the morning, isolated rains will continue to occur in the south of the Nicoya Peninsula and nearby areas. In the afternoon, isolated but strong showers with thunderstorms are expected, particularly for the mountainous areas in the Central Pacific, the South Pacific and around the Gulf of Nicoya, the Tempisque Valley and mountain ranges in the North Pacific, estimated amounts between 20 - 50 mm with possible maximum localized amounts of 80 mm. For the Central Valley and the Northern Zone, rain and showers with thunderstorms are expected, estimated maximum amounts between 10 - 50 mm, possible larger amounts of up to 70 mm. In the mountains of the Caribbean and surrounding low areas, the presence of very localized showers with thunderstorms with amounts between 10-45 mm is possible.

In addition, global numerical models continue to show the possibility that this wave will destabilize the ITCZ ​​over the weekend, consequently creating a rainy environment with more widespread heavy showers in the country on Saturday and Sunday.

Warning: Soils remain saturated in areas of the South Pacific, the Nicoya Peninsula, and the mountains of the Northern Zone, which increases vulnerability in these areas. In addition, the projected rains in urban areas may cause sewer saturation and flash flooding in the Central Valley and surrounding areas.

Due to the above, the IMN recommends: • Caution due to sewer saturation in places prone to this type of flooding. • Prevention in the event of an electrical storm and seeking shelter in a safe place in the event of strong gusts of wind occurring or perceived near the storm clouds, due to the possible fall of tree branches, power lines, among others. These gusts can reach 80 km/h in some isolated cases. • Stay informed through social networks, Twitter: @IMNCR, Facebook: Instituto Meteorológico Nacional CR and the WEB Page: www.imn.ac.cr

Gabriela Chinchilla Meteorologist DMSA-IMN

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