Summit County Citizens Voice

Experts: No reason to expect another record snow year, despite 2d-year La Niña

Will La Niña favor Colorado with good snowfall again this winter?

By Summit Voice

SUMMIT COUNTY — A second-year La Niña means the Colorado mountains have a good chance of getting close to normal snowfall, but an encore of last winter’s record-breaking snowfall is unlikely, according to Klaus Wolter, a meteorologist with the University of Colorado Climate Diagnostic Center.

Wolter, who studies the effects of El Niño-La Niña weather cycles on Colorado and the Southwest, predicted a return of La Niña last spring based on historic records that show strong La Niñas are often followed by a weaker version of the pattern, which is marked by cooler-than-average sea surface temperatures in the central and eastern equatorial Pacific.

This illustration shows a comparison between 1st and 2d-year La Niña patterns in the October to December period.

Wolter said the bottom line for the medium-range outlook is that, in Colorado, second-year “La Niña winter half-years are often drier than in the previous year. There is little evidence that would support a contrary (wet) viewpoint,” he wrote in the latest edition of the Climate Diagnostic Center’s Colorado and interior Southwest forecast. “his statement does not factor in ‘rogue atmospheric river events’ (like the one in December 2010) that are currently not predictable at the seasonal time-scale,” he added, referring to pineapple connection-type event that brought a period of heavy precipitation to parts of the West.

During 2d-year La Niñas, odds are for near-normal snowfall in Colorado.

Notwithstanding an early winter-like storm in the short-term forecast, NOAA’s Climate Prediction Center is calling for above normal temperatures and below normal precipitation for the October-December period.

A return of La Niña could extend drought conditions across Texas, the south-central states and the Southeast.

Critically, a second winter of La Niña conditions could bring an extension of the drought in parched areas like New Mexico and Texas, which is currently experiencing its most severe wildfire season on record.

This material was adapted from information provided by Klaus Wolter at NOAA-ESRL PSD, Boulder, Colorado, from his website at http://www.esrl.noaa.gov/psd/people/klaus.wolter/SWcasts/.

Filed under: climate and weather, Colorado, Environment, La Niña, Summit County news, Summit County snow and weather Tagged: | Climate Prediction Center, Colorado winter outlook 2011, El Niño-La Niña, Klaus Wolter, National Oceanic and Atmospheric Administration, Summit County News, University of Colorado Climate diagnostic center