What’s with the high winds in Vail and Eagle County?
Warm weather and strong gusts have taken a toll on local snowpack
Spring in Eagle County is usually breezy, but it has been unusually windy of late. The National Weather Service office in Grand Junction reported Sunday a wind gust of 61 mph at the Eagle County Regional Airport. Wind speeds were in the 50s and 60s around the region.
But the steady-state winds have been strong and persistent.
Lucas Boyer, a forecaster at the National Weather Service’s Grand Junction office, said he’s been “fielding a lot of phone calls” about the wind from around the region.
It was the wind that quickly whipped the human-caused April 16 Duck Pond Fire into a home-threatening conflagration in what seemed like a matter of minutes.
The cause, Boyer said, is the jet stream — which flows west to east across North America — is currently penned in by a couple of air masses, one in the western U.S. and the other in the Midwest. That’s keeping surface winds up, Boyer said. The winds in lower elevations tend to get stronger as daytime temperatures rise.
“We’re in one of those periods of change-resistant weather,” Boyer said. There could be a change coming by the end of this week, Boyer added. But while the winds may moderate, there still isn’t much chance of significant moisture.
Temperatures are staying warm and the relative humidity is low around the region. Temperatures, humidity and wind are the prime ingredients in red-flag fire weather warnings. But Boyer said so far this week the only such warnings issued by the Grand Junction office have been in the southwest corner of Colorado.
That can change quickly, though.
Tough on the snowpack
Besides being unpleasant, strong winds also play havoc with the local snowpack. Strong winds and warm temperatures can quickly suck moisture from the ground back up into the atmosphere.
In addition, the dust kicked up by the wind can settle on snow fields, making that surface less light reflective, and easier to melt.
Snowpack is commonly measured in “snow water equivalent,” meaning how much moisture that snow contains.
The numbers for three of the upper valley’s measurement sites haven’t been awful over the winter, but have lagged behind the 30-year median numbers for much of this snow season. The current combination of wind and warmth has dropped those numbers even more.
The Vail Mountain measurement site as of May 9 was at 63% of that 30-year normal.
The site at Copper Mountain — the closest site to the top of Vail Pass — was at 80% of normal as of May 9. The Fremont Pass site — the closest site to the headwaters of the Eagle River — was at 87% of normal on May 9.
Snowpack usually vanishes pretty quickly this time of year, but a nearly 25% drop in the Vail Mountain site’s snowpack between May 6 and May 9 is worrisome.
We’ve been behind
Diane Johnson, communications and public affairs manager for the Eagle River Water & Sanitation District, said an even bigger concern is the gap between the normal and current readings.
The normal reading for the Vail Mountain site is about 20 inches of snow water equivalent this time of year. This season’s reading peaked at only about 17 inches, then dropped from 15.2 to 11.4 inches in just three days.
That means local water supplies are already behind. The difference in those graph lines represents “a lot of water,” Johnson said, adding that if the trend of the past few days continues, that’s even more water that won’t end up in Gore Creek and the Eagle River.
Then there’s the question of how much water is being wind-stolen back into the atmosphere and how much is sucked into dry soil before eventually flowing into local streams.
The fact is “we’re living with less” runoff, Johnson said. But, she added, it’s still too early to start outdoor irrigation systems but it is time — and has been for a while — to rethink outdoor landscaping.
63%: May 9 percentage of normal snow water equivalent on Vail Mountain.
80%: May 9 percentage of normal snow water equivalent at Copper Mountain.
87%: May 9 percentage of normal snow water equivalent at Fremont Pass.
25%: Decline in Vail Mountain snow water equivalent from May 6 to May 9.
Sources: Eagle River Water & Sanitation District, U.S. Department of Agriculture.