El Nino pushes state snowpack higher in south, lower elsewhere
The seemingly endless run of January storms wasn’t enough to raise Colorado’s snowpack even to long-term average.
Most of the storms hit southwestern Colorado, thanks to an El Nino weather pattern that tracks storms to the south. That means that while Telluride Ski Resort and Crested Butte Ski Resort enjoyed plenty of snowy days, most of the central and northern mountains were bypassed.
The result, said Allen Green, state conservationist with the National Resources Conservation Service, is the latest snow surveys show slightly above average totals in the southwestern mountains while snowpack percentages decreased elsewhere across the state.
Green said Colorado’s statewide snowpack was 86 percent of average as of Feb. 1, which is 73 percent of last year’s snowpack totals on this same date. He said this month’s percentage is the lowest since 2003.
Snowpack in the Colorado River basin declined by 9 percent since the Jan. 1 snow surveys.
A typical El Nino pattern pushes moisture inland from the California coast into Arizona and New Mexico. Green said these storms brushed southwestern Colorado but did not benefit basins to the north.
The greatest increase in snowpack percentages was found in the Rio Grande and the combined San Juan, Animas, Dolores and San Miguel basins.
“The remainder of the state continued to stagnate with only minor increases during the latter half of January,” Green said.
As the winter progresses, the outlook for water supplies continues to point toward below normal runoff volumes, especially in the river basins across northern Colorado, Green said.
“The outlook for runoff in the Upper Colorado, North Platte, Yampa, White and South Platte rivers continues to call for well below average flows,” Green said.
During the recent Aspinall Unit Operations meeting in Montrose, the Bureau of Reclamation reported that as of Jan. 20, snowpack in the Gunnison Basin is 79 percent of average and 83 percent of average for the basin upstream of Blue Mesa Reservoir.
Blue Mesa Reservoir is expected to fill this spring, said Dan Crabtree, chief of the Water Resources Group in Grand Junction. He also emphasized that with so much of the snow year ahead, the forecast may change between now and May 1.
According to the Grand Junction Weather Forecast Office, an El Nino brings:
A tendency toward a drier winter, especially across the north.
Below normal precipitation during the December through February period, especially across the north, with the exception of the Front Range.
Increased storminess during the March through April period.
Warmer than normal conditions.
A more southerly storm track favoring the Four Corners region.