Snowpack down sharply since March 1
April 1, 2009
Recent storms provided a fittingly lion-like end to March, but due to a predominance of lambish conditions for two months, snowpack in the high-elevation mountains above Middle Park now ranges from 88 to 127 percent of the 30-year average, down sharply since March 1.
“This resumes the pattern of weak spring snows observed during 2005 to 2007, despite the fact that March is historically the snowiest month,” said Mark “Doctor” Volt, District Conservationist. “The April 1 readings are the most critical for predicting runoff and summer water supplies, as most of our high country snowpack peaks during April.”
The highest local readings are in the Blue River sub-basin (average 115 percent), and the lowest readings are in the northern drainages.
Snow at lower elevation in Middle Park has mostly melted and does not reflect the near-average snowpack conditions at higher elevation.
Snow density is averaging 31 percent, which means that for a foot of snow there are 3.8 inches of water.
In Colorado, only the northwestern river basins are above average. The highest snowpack, relative to normal, is in the Little Snake sub-basin of the Yampa River, and the Blue River and Roaring Fork sub-basins of the Colorado River. Reported readings for the major river basins in Colorado are as follows: The upper Colorado River Basin averages 108 percent; Gunnison River Basin, 92 percent; South Platte River Basin, 89 percent; Yampa River Basin, 104 percent; White River Basin, 101 percent; Arkansas River Basin, 96 percent; Upper Rio Grande Basin, 92 percent; San Miguel, Dolores, Animas, and San Juan River Basins 88 percent; and the Laramie and North Platte River Basins, 96 percent of average for this time of year.
Most of the snow courses around Middle Park have been read since the 1940s. Snow course readings are taken at the end of each month, beginning in January and continuing through April.
For further information, including real-time snow and precipitation data for SNOTEL (automated Snow Telemetry) sites, visit http://www.co.nrcs.usda.gov/snow/index.html.