Odds improving for El Niño this year

...Since mid-February, forecasters have been watching an expanding pool of warm water in the eastern Pacific, growing more confident that El Niño is on the way. When it arrives, its big, warm pool of ocean water changes weather patterns across North America for as much as a year. Generally, it makes New Mexico wetter. But the devil is in the details. Last Thursday’s monthly forecast by the federal government’s Climate Prediction Center was the agency’s most confident yet, with a 65 percent chance that we’ll get an El Niño by summer and a nearly 80 percent chance that it will show up by autumn. New Mexico water managers need some good news. Last year, the Rio Grande was close to dry by the end of June before a good burst of monsoon rains in early July bailed us out. This year, with reservoirs further depleted and our fourth consecutive abysmal winter snowpack, the water scramble is again underway as managers try to stretch their supplies, hoping for summer rains. “It’s going to be another very tight year,” said Mike Hamman, head of the Bureau of Reclamation’s Albuquerque office. Could El Niño tip the odds of good summer rains in Hamman’s direction? In 1997, as the last big El Niño was getting underway in a pattern very similar to what’s going on today, the summer rains in Albuquerque started in June and the weather was consistently wet through September. But in 1982, another similar year, summer rains were a mixed bag across the state, according to Andrew Church, a forecaster at the National Weather Service’s Albuquerque office who has been following El Niño’s development. The last El Niño began in the summer of 2009, and it was a wet monsoon season across most of New Mexico, according to Church. In general, in years when El Niño looks like the current one, New Mexico’s summer rains tended to be above average, according to Klaus Wolter of the federal government’s Earth Systems Research Laboratory in Boulder, Colo. But not always. In 1984, it looked like El Niño was getting cranked up in the spring, only to fizzle by summer. New Mexico had below-average summer rains that year. Church thinks that, in addition to a brewing El Níño, there’s a second factor working in favor of a good summer rainy season. In an interview last week, he pointed on his maps to unusually warm water along the coast of North America. When those two features combine – warm water along the equator and warm water along the coast – they tend to give summer rains here a boost, Church said...more