Mountain snowpack off to above-average start

Snowpack levels and water supply projections are off to an above-average start in the mountains of eastern Idaho and across much the state, according to a Tuesday report from the Natural Resource Conservation Service.

At winter’s halfway mark, water supply officials feel optimistic about 2017 after an especially stormy December. Eastern Idaho and western Wyoming had among the highest snowpack percentages in the state, according to the report, which covered October to Jan. 1.

“It’s all adding up to good news right now, this early in the season,” said Ron Abramovich, a water supply specialist with the NRCS, part of the U.S. Department of Agriculture.

Upper Snake River Basin snowpack levels mostly stood between 110 and 125 percent of the median for this time of year. Measurements in western Wyoming showed values as high as 142 percent of average. For snowpack readings, officials measure the “snow-water equivalent,” or water weight, of the snow at various mountain locations.

The central part of the state, draining into the Wood and Lost River basins, was lower than eastern Idaho, hovering near average. Meanwhile, mountainous regions in southern Idaho near the Utah border ranged between 97 and 132 percent of the median snowpack for Jan. 1.

The panhandle region is the driest so far, with snowpack values as low as 72 percent of normal.

Streamflow forecasts — providing a strong water supply indicator for irrigation and other purposes the rest of the year — showed mostly average and above-average values around the state.

In eastern Idaho, October was wet and even saw significant snowfall in the mountains. That was followed by an abnormally dry and warm November. Then December struck, bringing back-to-back snowstorms that helped “catch back up” on snowpack totals, Abramovich said.

“We were a little behind getting started here, but the storms have come in strong and brought abundant moisture,” he said.

The report said Idaho’s reservoirs are generally in “good shape” and are “ready to catch any early season melt and runoff that may occur from the rain and melting low elevation snow.”

But Abramovich warned the wet weather must continue. Last winter got off to a similarly positive start for snowpack and water supply. But that advantage largely disappeared with a warm and dry spring, leading to water supply issues late in the growing season.

“We don’t want the storms to quit yet,” he said.

Luke Ramseth can be reached at 542-6763. Twitter: @lramseth