Experts: El Niño is coming

From the print edition

Due to the weather phenomenon El Niño, Costa Rica’s rainy season will be one of the driest in years, according to weather experts. 

The National Meteorological Institute (IMN) announced this week that the final six months of the year will be drier than average in most of the country. The most significant decrease in precipitation will occur in the Central Valley and the northern Pacific coast. 

Only the Caribbean coast will see an increase in wet conditions. The El Niño climate pattern has been expected to build in 2012. Meteorologists said in recent weeks that the pattern, which causes a heating of the Pacific Ocean’s surface, is going from a “neutral stage” to an active one. The result means less rain and hotter temperatures for the Pacific coast.

“These conditions will be maintained for at least the next three months,” said IMN meteorologist Eladio Solano. 

Solano said he expects some slight variations in El Niño’s behavior, but overall the phenomenon will bring higher temperatures and little rain to the Pacific, Central Valley and Northern Zone until the rainy season ends in November. 

By contrast, the Caribbean may see a surplus of precipitation of 20 percent above average. El Niño also is associated with a decrease in hurricanes on the region’s Atlantic coast. So far, four tropical storms have formed at a frightening speed this year. Meteorologists predict that El Niño will slow the formation of hurricanes in upcoming months, during the peak of hurricane season. Experts predict 13 tropical storms or hurricanes in total for the 2012 season, which runs from June 1 to Nov. 30.

While hurricanes rarely cause major damage in Costa Rica, increased heat could harm farmers on the Pacific coast. The Central American Agricultural Council on Tuesday alerted regional authorities about El Niño in the area and its potential effects on agriculture and livestock. The northwestern province of Guanacaste is already the driest part of the country, and the IMN predicts 20 percent less rain for that region. 

Rainfall could drop by 15 percent in the Central Valley and 10 percent on the central Pacific coast. The Northern Zone and southern Pacific will see only slight drops in precipitation.

According to Erick Quirós, an expert at the Agriculture and Livestock Ministry, the change in weather conditions could cause economic problems for the sector, and ministry officials are developing a contingency plan to help mitigate damage.

Reports said that the meteorological center at Juan Santamaría International Airport outside of San José recorded in the first half of the year the third-driest temperatures in the last three decades.

In the first 10 days of July, Solano said, the Central Valley and Guanacaste experienced 50 percent less rainfall than normal.

“These figures could be maintained throughout the month and even during the first days of August,” Solano added.

Still, he said, El Niño will not make Costa Rica’s rainy season into an arid, desert-like atmosphere. When rain does fall, it will be more intense than average, and could lead to flooding, landslides and other problems related to downpours. These sporadic rains are brought on by trade winds known as the “Pacific breeze,” Solano said.

The meteorologist said residents of the Caribbean region need to watch out for flooding and take cautions to remain safe during heavy rains.