Even before Thursday storm, snowpack levels above averageDec 19, 2013 From staff reports
Snowpack in the Wind River Basin continued to be above the 30-year average for the date, although fells slightly during the week following an increase as the month began.
Weekly figures from the Wyoming Natural Resources Conservation Service tabulated snowpack at 113 percent of average snowfall from 1981-2010 in the Wind River drainage. The report is dated Dec. 16 -- before Thursday's snowfall began.
Last week's reading was 119 percent, which was an increase from 117 percent on Dec. 2.
The figures are running ahead of last year's average, which was 101 percent on Dec. 16, 2012, and 102 percent on Dec. 9, 2012.
The averages are calculated from an average taken from several different measuring stations in the mountain areas draining into or drained by the Wind River. Snowpack readings were spectacular in the early weeks of fall as four significant snowstorms arrived from late September to late October. Conditions have been more dry since then, although there was significant mountain snowfall accompanying the dramatic temperature downturn early in December. Only three of the 19 drainages monitored by the state had readings below 100 percent of average. Lowest was the Upper Bear River drainage in southwest Wyoming near the state's border with Idaho and Utah at 81 percent, down 10 from the week before but up from Dec. 2.
The lower Green River drainage near Flaming Gorge also came in under 100 percent, registering 92 percent as of Monday, down from 105 percent last week. And the Sweetwater drainage, which includes part of southern and eastern Fremont County, was at 94 percent of average, down from 102 percent last week.
The statewide average was 122 percent, down from 130 percent last week and 131 percent two weeks I ago. Those figures look much healthier than a year ago, when the Dec. 16 average was 81 percent.
The biggest percentages were in the Bell Fourche drainage at 236 percent of average, more than double the 110 percent recorded last week. The Cheyenne drainage at 160 percent and the Bighorn Basin drainage at 141 percent were the next highest, although they both had decreased from last week.
Only the Tongue River drainage, up to 121 percent from 118 percent a week ago, joined the Belle Fourche in the growth category for the week.