El Nino brings precipitation, but no long-term drought relief

BOULDER — You know the adage: If you don’t like the weather in Colorado, wait five minutes. While you might have to wait a little more than five minutes, meteorologists say change is coming.

Short-term drought relief is on the way, said meteorologists at the National Oceanographic and Atmospheric Administration — Cooperative Institute for Research in Environmental Sciences Climate Diagnostics Center in Boulder.

A wet fall and spring are likely because of El Nino, a periodic disruption of the ocean-atmosphere system in the tropical Pacific that tends to have important consequences for weather and climate around the globe.

However, Climate Diagnostics Center Director Randall Dole was pessimistic regarding long-term drought relief. “It is very unlikely that a wet winter will be able to build reservoirs up to normal levels,” Dole said.

“It took us three years to get into this situation,´ said meteorologist Klaus Wolter. “It will take awhile to get out of it.”

According to NOAA scientists, there have been 10 “extraordinary” El Ninos during the past 50 years that have had more impact than average ones. The fact that the El Nino we’ve been experiencing since late April appears better than average should have a positive affect on precipitation levels, Wolter said.

Historically, El Nino conditions have been associated with wetter than average conditions for November, March and May in both the Front Range and Western Slope regions of the state. Since much of Colorado is dependent on direct runoff and water diversion from the Western Slope, this bodes well for the state. “The bigger the El Nino, the better the odds for precipitation,” Wolter said.

Additionally, Colorado experiences fewer Chinook winds during El Nino, Wolter said. That should lead to a colder fall, which in turn should cause any precipitation that does fall to occur in the form of snow. Wolter said he was “cautiously optimistic” for the ski industry both early and late in the season.

The drought that has plagued the United States and most of the Northern Hemisphere for the past four years has been caused by elevated sea surface temperature patterns during the same time frame, said meteorologist Martin Hoerling. Higher sea temperatures are related to increasing carbon dioxide levels in the atmosphere, he said. This degree of ocean warming is “not consistent with natural variations, but is consistent with human activities,” Hoerling said.

While NOAA scientists acknowledged that their findings might be interpreted as a dire warning for humanity, they make neither predictions nor policy recommendations. “We provide science information,” Dole said.

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