Will the Vail Valley be affected by the ‘official’ El Nino pattern? | VailDaily.com

Will the Vail Valley be affected by the ‘official’ El Nino pattern?

While the pattern has finally developed in the Pacific, its impact for spring and summer are unclear

What’s an El Nino? An El Nino — and it’s La Nina counterpart — is weather pattern that begins in a part of the Pacific Ocean west of South America. El Nino is marked by warmer-than-normal water temperatures in that region. La Nina is marked by cooler-than-normal water temperatures. Source: National Oceanic and Atmospheric Administration.

EAGLE COUNTY — The little boy has arrived.

The National Oceanic and Atmospheric Administration recently announced that a portion of the Pacific Ocean west of South America has officially entered an El Nino (Spanish for “little boy”) pattern. That could be good news for southwestern Colorado, and could bring some benefits to the central Rocky Mountains.

According to a release from the federal climate center, the El Nino climate pattern has taken effect, and is likely to continue through the spring.

Climate watchers have been waiting since the fall of 2018 for the pattern to take hold.

Scott Stearns, a forecaster in the Grand Junction office of the National Weather Service, said an El Nino starts with warmer-than-normal water temperatures. But, he said, the atmospheric temperatures for some time didn’t warm up along with the water temperatures. Those two things have to mesh to create a true El Nino.

“That’s a decoupling we don’t see very often,” Stearns said.

Now that the water and atmosphere are both in the El Nino range, it’s not exactly clear what that means.

Hard to predict outcomes

If an El Nino or La Nina develops in the late summer or early fall, there’s some predictability as to what kind of wind and storm patterns may develop.

When the phenomenon develops late in the season, there’s more uncertainty, particularly regarding summer storms.

Stearns said winter patterns don’t carry over into the summer months.

Summer weather is more dependent on seasonal monsoonal flows that carry across the southwestern U.S., he added.

The effects of an El Nino that lingers into the summer is still being studied, he said.

The federal climate prediction center is calling for a chance of above-average temperatures and above-average precipitation. Those forecasts aren’t always accurate — the center predicted a chance of above-average precipitation in the summer of 2018, and that didn’t happen.

Still, it’s a good sign. Maybe.

Local impact

Diane Johnson, the Eagle River Water & Sanitation District’s communications and public affairs manager, said the sleet, drizzle and above-freezing temperatures around Feb. 14 are exactly what we don’t need right now.

“The biggest thing right now is that I hope our precipitation is snow,” Johnson said.

Johnson created a chart of the snow water equivalent measurements for Feb. 15 at the Vail Mountain measurement site.

The 30-year median is 11.9 inches of snow water equivalent at the Vail Mountain site. The measurement for Feb. 15 of this year was 13.5 inches. That measurement is about 60 percent of the seasonal median.

This year’s measurement is good, and certainly far better than the 8.3 inches of snow water equivalent measured at Vail on Feb. 15, 2018.

Still, this year’s number is less than the 2017 number on Feb. 15.

And, Johnson said, the important thing to look at is when the snow water equivalent, or water contained in snowpack, peaks for the season.

The peak snow water equivalent in 2017 was a bit below the 30-year median, but it peaked on March 11. The median peak comes about April 25.

That’s important for summer water supplies.

That means while many of us enjoyed a bit of above-freezing temperatures recently, it has to stop, whether or not El Nino brings above-average snowfall.

“We live at 8,000 feet (in Vail) — it’s supposed to be cold,” Johnson said. “We want it to be cold, and we want the snow to keep coming.”

Vail Daily Business Editor Scott Miller can be reached at smiller@vaildaily.com or 970-748-2930.

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