Runoff peaking in Vail following ordinary, yet extreme, snow season
While snow totals were below average, 2018-19 season was extreme in several ways
For a ski area that recorded less-than-average snowfall totals this season, the white patches are certainly persisting on Vail Mountain.
Vail closed on April 21 with a total of 281 inches recorded, well shy of the mountain’s average of 350 inches. Snow continued to fall, however, and by June 4, when the SNOTEL recording site on the mountain has usually melted out, there was still plenty of snow there. The site, located near the Pika run, didn’t end up melting out until June 12.
On Friday, the first day of summer, a glance at the mountain still revealed quite a bit of snow on the mountain’s upper elevation runs, like Riva Ridge, Highline and Whistle Pig. That snow will eventually reach local waterways. While many had thought streamflows on the Eagle River near Minturn had reached their peak on June 14, sustained rain events during the week that followed pushed flows up once again, and by June 20 the daily mean discharge was back up to 1,220 cubic feet per second, about where it was on June 14.
As of June 20, the mean daily peak on Gore Creek at the Red Sandstone Creek recording station looks to have occurred on June 19, when the daily mean discharge was 1,110 cubic feet per second.
Rain makes an impact
Diane Johnson with the Eagle River Water and Sanitation District said statewide, forecasters had observed the June 14-15 time period as peak runoff based on how much snow was remaining in the high country. But in Vail, “getting that extra sustained rain right on the tail end of when a lot of snow was coming down pushed it back,” Johnson said.
Johnson said rain events that are high intensity over short periods of time can cause spikes at the runoff recording stations, but they won’t contribute much to the mean discharge over the course of a day.
However, “Monday’s and Tuesday’s rain did not spike the flows, it increased them over the next couple of days,” Johnson said. “It really had a lasting effect.”
Average, yet historic
While our area may look ordinary in terms of snowfall totals in 2018-19, the region was subject to extreme weather events which climate scientists predict will become more regular in the years to come.
Brian Lazar with the Colorado Avalanche Information Center said several avalanches that occurred this season were bigger than anyone has ever seen in Colorado.
“To see an avalanche cycle that was so widespread, over a week or two in March, you could say that nobody alive has seen that happen,” Lazar said. “The one that ran at Peak 1 outside of Frisco … that rejuvenated an avalanche path that hasn’t been cleared out like that in over 100 years.”
Lazar said while he never thought he’d see a season like this one, it does fit into the larger pattern of extreme weather.
“Increased storm severity — warmer, wetter, juicer storms — are consistent with climate science,” Lazar said. “And so it would comport with the current climate science to see these types of storms become more frequent as we move into the future.”
On the other end of the spectrum, current climate science also predicts the peak runoff will start occurring earlier and earlier in Eagle County, and that’s definitely not the case this year.
The local waterways usually peak around June 5-6, making us about two weeks behind what’s normal in Vail.
What’s normal, however, has become a bit of a moving target.
“One of the expectations of climate change, and the trends we’ve been seeing, is an earlier peak, an earlier melt,” Johnson said. “And that messes up the natural timing of things — you want runoff in June, you don’t want it in May.”
This year, Johnson said the Eagle River Valley can be hopeful for healthy streamflows to last through the summer.
“But you never know,” she said. “We could still get low streamflows in August.”
As for now, Gore Creek is running at about twice the normal flow for this time of year, while the Eagle River near Minturn is about three times the normal flow.
For those coming into town for Independence Day, the Vail Lacrosse Shootout, or one of the many other signature events for this time of year, “they might be used to seeing the river at a lower level, and they might be caught by surprise,” Johnson said. “So it’s probably worth having some extra messaging around that public safety issue.”