How much will it snow?
The answer depends on Colorado’s geographic location as much as weather trends, experts say.
Will have a snowy winter? They offer a definite “maybe.”
“In the southern Rockies it will be wetter than normal and in the northern Rockies, drier than normal,” says Mike Halpert of the National Center for Environmental Prediction. “It’s never a sure thing.”
Colorado’s precipitation and temperature cycles are often heavily influenced by a cyclical warm Pacific Ocean current known as El Nino.
“As winter approaches, an El Nino cycle is forming, and that typically means it will be warm in the north and wet in the south,” Halpert says. “Colorado falls somewhere in the middle, where things are not that well-defined.”
In short, that means it’s a toss-up.
El Nino is a warming of the ocean in the equatorial Pacific that shifts rainfall patterns in the Tropics, as well as the moisture-directing jet stream, a high-altitude wind that moves weather patterns over the Americas. How far north or south the jet stream moves determines moisture levels here, experts say.
“Last year, (moisture) conditions in the southern part of the state were terrible,” says Mike Gillespie Snow Survey Supervisor of the Natural Resource Conservation Service. “This year we may see a reversal of that.”
Last winter was the fourth -driest in history, adds Lay Lawrimore, of the National Climatic Data Center. “It’s not out of the question that you could go more than five years at a time (with less-than-average precipitation).”
In April, Eagle County’s snowpack was at 65 percent of normal, but warmer-than-normal temperatures and less-than-normal precipitation in spring caused streamflows to shrink.
It was the fifth year of below-normal snowpack, said Gillespie. The last above-normal snowpack year was 1997. Snowmelt supplies 70 percent of the water used in and out of Colorado.
Flows of the Eagle River and Gore Creek, the two main water supplies for eastern Eagle County, have been bolstered by recent rain and snow.
What has surprised water experts is how much water continues to flow.
The Eagle River Friday morning at Avon was flowing at 141 cubic feet per second, or cfs, 122 percent of the long-term mean; Gore Creek at Vail was flowing at 32 cfs, 106 percent of normal.
“We’re pleasantly surprised at how well it has held up,” says Hydrologist Bob Weaver of Enartech in Boulder.
The healthy streamflows are the opposite those this summer, which coincidentally is the peak of water use in Eagle County.
With the unpredictability of precipitation, ski resort operators will be counting on a combination of natural snow, man-made snow and even cloud-seeding to keep slopes white.
Last year Vail made snow on 380 of its 5,289 skiable acres, while Beaver Creek made snow on 605 of its 1,605 acres. Those totals will likely grow as terrain is added.
In Summit County, Keystone had 956 snowmaking-covered acres out of 1,861 and Breckenridge had 516 of its 2,208 skiable acres covered by snowmaking.
Snowmaking is used to cover many of the popular trails at low elevations. Generally, trails at higher elevations typically are covered adequately by natural snow. Snow is typically made from mid-October to January.
Vail Resorts has used 12 ground-based cloud-seeding generators on and near Vail and Beaver Creek for nearly 25 years.
“A rising tide floats all boats,” says Vail Resorts’ Paul Testwuide. “We’ve got it in the back of our mind that these things work once in a while. You will see sections of Vail Mountain with considerably more snow than other areas.”
Even if the snow from seeding operations doesn’t fall on the ski mountains, the resulting runoff benefits area streams, Testwuide adds.
Computer modeling of national precipitation patterns shows snowfall may be greater than last year just south of Vail, but not by much.
Gillespie, meanwhile, remains optimistic: “We’re looking at a moderate El Nino this year. Usually when we have that we have the best opportunity for heavy precipitation in southern Colorado and northern New Mexico. In many years we get lucky and it extends north. There’s hope.”
Cliff Thompson can be reached at 949-0555 ext 450 or firstname.lastname@example.org