If you live in or are traveling through the Central Valley, the Pacific coast or the Northern Zone, you are now under a yellow alert for rain. The National Emergency Commission (CNE) raised five regions from green to yellow yesterday, and the National Meteorological Institute (IMN) expects another wet day today on ground that can barely take more water.
The regions on yellow alert are the North Pacific, Central Pacific, South Pacific, Central Valley and Huetar Norte, which covers the Northern Zone. The Caribbean stays on green. That is a step up from yesterday morning, when the whole country was still on green alert even as the chance of a tropical depression was fading.
Why the upgrade? It comes down to soil. CNE president Alejandro Picado said the low-pressure system off the Pacific coast kept pushing showers and storms ashore from Thursday night. Soils on the Pacific slope are now 80% to 95% saturated, according to the commission. When the ground is that full, rain runs straight into rivers, ditches and drains instead of soaking in.
The numbers from Thursday night into yesterday show how fast it adds up. The IMN recorded 20 to 50 millimeters (0.8 to 2 inches) across Guanacaste and Puntarenas in 12 hours. Hojancha took 111 mm (4.4 inches) and Barú 56 mm (2.2 inches). Yesterday morning, local emergency crews handled incidents in San Carlos, Fraijanes, Poás, Alajuela and Sarapiquí, mostly overflowing sewers. The CNE said no one had to be evacuated.
For today, the IMN said the low near the Pacific coasts of northern Costa Rica and Nicaragua will keep the atmosphere unstable. Expect rain from early morning along the Pacific coast. In the afternoon, showers and thunderstorms spread to several regions, including the Caribbean and the Northern Zone. The Central Valley should get scattered rain, with occasional thunder in the east.
Guanacaste is the area to watch this weekend. The IMN warned that rain along the Pacific coast can come in bursts of 30 to 60 mm (1.2 to 2.4 inches) within six hours, especially in the North Pacific. Isolated gusts can reach 80 km/h (50 mph), which is enough to bring down branches, signs and power lines.
It will stay cool in the capital. The IMN forecast a high of 24.7 C (76 F) and a low of 18.5 C (65 F) in San José today. Liberia should reach about 33 C (91 F), and Quepos about 28 C (82 F).
The storm system itself is weakening. In yesterday’s outlook, the U.S. National Hurricane Center cut the odds of a tropical depression to 30% over both the next 48 hours and the next seven days. That is down from 40% on Thursday night and from the 60% chance it carried earlier in the week. The center said conditions will turn increasingly hostile over the weekend, but warned the system can still bring heavy rain to parts of Central America.
So what should you do? Plan outdoor time for the morning, when storms have been weaker. Never drive or walk through a flooded street, river or ravine, because you cannot judge depth or current until you are in it. On mountain roads, slow down for fog, fallen trees and small landslides, which are more likely when hillsides are this wet.
On the coast, the risk is on the water too. The CNE asked small fishing boats and tourism operators to watch sea conditions closely. That follows several days of rough surf on the Pacific beaches. If a boat tour or surf lesson is in your plans, ask the operator about conditions before you go.
Yellow alert means local emergency committees are active and ready to respond, not that a disaster is under way. Forecasts for systems like this can change quickly, so anyone with weekend plans should check the latest IMN update before heading out and call 911 in an emergency.
