El Nino To Affect Weather In Colorado And Western U.S.

December 1, 2006

Colorado's late fall snowstorms could disappear by mid-December due to the influence of an El Niño event in the tropical Pacific Ocean, said Klaus Wolter, a University of Colorado at Boulder and National Oceanic and Atmospheric Administration scientist.

"Sometime in December I would expect to see the classic El Niño winter doldrums where the storm track shifts so far south that we might run dry for a very long stretch, maybe several weeks where nothing happens," said Wolter.

According to Wolter, the current El Niño is showing signs of strengthening. El Niño events occur when temperatures on the surface of the eastern tropical Pacific are warmer than normal for several months.

The wetter-than-normal weather Colorado experienced in October was typical of a moderate to strong El Niño event, he said.

"In the Front Range you have these two bookend months -- October and March -- where a good-sized El Niño can produce above-normal snowfall," he said.

According to Wolter, the dry, mid-winter conditions usually reverse as spring approaches, typically in late February or early March. And when the storms return, he said, they can bring a lot of moisture with them.

"March has a tendency to produce copious snow amounts with El Niño," said Wolter. "And another characteristic of El Niño springs is that the Front Range is more than likely to be on the wet side."

He also said that Arizona and New Mexico could get a wet winter in stark contrast to the record drought they experienced last year.

Source: University of Colorado