San José, Costa Rica, since 1956

‘Green’ Season Is Coming Early

After spurts of rain in February, meteorologists forecast this month will likely remain “dry” as the dry season dictates.

But come April, the Pacific region and Central Valley are in for a surprise: an early rainy season.

The rainy season, also known as “green” season, could begin between April 21 and 25 in the north Pacific and April 26 and 30 in the central Pacific and Central Valley regions, according to Rebeca Morera, of the National Meteorological Institute (IMN).

That’s at least 15 days earlier than normal.

In the southern Pacific region, which normally sees the first of the showers, the rains could begin as early as March 12.

Morera said La Niña is to blame. La Niña (The Girl in Spanish) is a phenomenon characterized by unusually cold sea-surface temperatures in the eastern equatorial Pacific.

La Niña began dragging down temperatures during the last quarter of 2007, according to Costa Rican meteorologists and weather analysts worldwide.

Sydney, Australia, is experiencing its coolest summer in 50 years, and La Niña is believed the culprit, the newswire Bloomberg reported. Some analysts blame it for southern China’s recent freeze.

Weather here, on the other hand, has been odd but not as extraordinary, having calmed after the treacherous storms and floods of last year’s wetter-than-normal green season (TT, Oct. 19). The meteorological institute downplayed February’s rainy spell, saying the country as a whole, though seeing more rain than normally, has actually experienced less precipitation than was forecast.

“Even during the dry months, sporadic rain is to be expected,” said IMN weather analyst Werner Stolz.

Looking at temperature, Stolz noticed a slight dip. “2008 has so far been 1 to 2 degrees (Celsius) cooler than normal.”

Lower temperatures, Stolz said, have particularly chilled the Central Valley. However, these decreases mainly occurred in the lows of the night, he said, which this dry season have hovered between 7 and 15 degrees Celsius (about 44.5 and 59 degrees Fahrenheit). The valley’s average lows this time of year are 8 to 17 degrees Celsius. Stolz cited Heredia, north of San José, as a town that has seen particularly low temps. On Jan. 30, it sank to 7 degrees Celsius.

The wind has also been stronger overall, blowing an average of 10 kilometers per hour, according to IMN. January registered winds up to 100 kph.

The wind likely will settle down now for the rest of the year, Stolz said.

Despite the early start, meteorologists are betting this green season won’t repeat the extreme weather that took its toll last year. That’s a relief to the National Emergency Commission (CNE), which with ¢36.618 billion (more than $70 million) is still repairing roads, bridges and homes damaged by the flooding.



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