Ron Abramovich measures water content of snow at More's Creek Summit, Jake Putnam photo
More Winter Storms needed to put water supply on track
Boise– The Natural Resources Conservation Service (NRCS) December snow survey shows current snowpacks in Idaho are 45-80% of average but only 20-30% of their seasonal peaks which occur in early April. Snow surveys are conducted at the end of each month from December through May to make snow runoff predictions and water supply forecasts used in managing Idaho’s water resources.
“Don’t be tricked by December’s cold temperatures,” said Ron Abramovich, NRCS Water Supply Specialist. “Those cold temperatures were accompanied by below normal precipitation. Currently, the snowpacks across the state are shallow.”
November, December and January are generally Idaho's biggest precipitation months, but November and December did not come through. November precipitation amounts were only 20-30% of average across southern Idaho and 40-60% in central and northern Idaho. December temperatures set record lows at many of Idaho’s SNOTEL sites; precipitation ranged from 45% of average to near average.
“With more than half the winter still to come, the water supply picture will hopefully improve,” added Abramovich. “Above average precipitation will be needed for the next three months to reach average snow water content amounts in the mountains by April,”
The highest snowpacks are 75-80% of average in the Panhandle region and the Weiser, Owyhee and Oakley basins. The lowest snowpacks are 45-55% of average in the Little Wood, Willow, Blackfoot, Portneuf and Bear basins, as well as the critical Snake River Basin above Palisades Reservoir. Elsewhere, snowpacks are 58-68% of average.
New Snow Survey Products and Updates
Two new streamflow forecasts were developed for the Gros Ventre River and Buffalo Fork, both tributary drainages to Upper Snake River in Wyoming.
NRCS installed a new SNOTEL site to automate the Pierce Ranger Station Snow Course originally established in 1951. Located in the Clearwater basin at an elevation of 3,080 feet, the site represents the mid-elevation area in the basin. Hourly data is available from our Web page for the soil moisture/temperature and snow depth along with snow water equivalent, precipitation, and air temperature.
Snow measurements have been discontinued at the Corner Creek and Sage Creek Saddle snow courses near Coeur d'Alene. These sites were originally established for a research project but are no longer needed. The two scheduled measurements at these sites will be estimated this year. Next year the sites will be removed from our reports.
Interesting and informative data, graphs and maps are available from our snow survey Web pages and are a great way to keep abreast of current conditions as they change throughout the year. Click on http://www.id.nrcs.usda.gov/snow/. For more information about snowpack, precipitation, runoff and water supplies for specific basins, please view the complete January 2010 Water Supply Outlook Report online at www.id.nrcs.usda.gov/snow and click on the ‘Water Supply’ link.