From The Vail Daily (Scott Miller):
Local lore holds that March is our snowiest, wettest month. That isn’t so.
Recent data from the National Centers for Environmental Information that covers the period between 1991 and 2020 show that, at least in the town of Vail, February is actually the snowiest month, with average snowfall of more than 35 inches. April is actually the wettest month, with an average of just more than 2.4 inches of precipitation.
That actually isn’t much of a change from the previous measured period, from 1981 through 2010.
State Climatologist Russ Schumacher wrote in an email that the change in the numbers is mostly seen in the western part of Eagle County. The wettest months had been in the fall in those lower-elevation areas. That shift is consistent with data across much of northwestern Colorado.
While April is the wettest month in terms of precipitation, that doesn’t necessarily equate to snowfall.
Schumacher noted that spring snow tends to be heavier, because there’s more water in that snow. The snow in mid-winter tends to be lighter, which is better for skiing but not great for accumulating water in the snowpack.
At the moment, the snowfall measurement station on Vail mountain is right at halfway toward its average peak “snow water equivalent.” That number usually peaks in late April at right around 20 inches. The Jan. 17 measurement was 10.1 inches at that site, 111% of the 30-year average. The other main measurement sites, Copper Mountain, near the headwaters of Gore Creek, and Fremont Pass, near the headwaters of the Eagle River, are in that range.
Aside from the moisture content of snow, does it really matter when it comes?
Diane Johnson, the communications and public affairs manager for the Eagle River Water & Sanitation District, said there’s a lot to consider when pondering when snowfall comes.
Johnson wrote in an email that snowfall’s impact on streamflow — the source of most of the valley’s domestic water — depends on what form precipitation comes. Snow and rain have different impacts. If the snow stays high and temperatures stay low, the spring snowmelt slows, providing more consistent supplies.
“We’ve been seeing earlier melts,” Johnson wrote. That affects streamflows not only in the spring and early summer but through the rest of the season.