Drought in Idaho: 2021 vs. 2022

Above-average snowpack totals across Idaho have helped offset severe-to-extreme drought conditions, shown here in orange and red. “Moderate” drought is represented in tan.

A pattern of intense snowfall from mid-December through last Friday has brought Blaine County down three tiers in federal drought classifications, reducing the chance that the county will again experience drought for a third straight year, according to a Thursday forecast from the Idaho Water Supply Committee.

On Thursday, the federal U.S. Drought Monitor listed Blaine County in “moderate” drought, the National Oceanic and Atmospheric Administration’s second tier after “abnormally dry.”

At the same time last year, most of Blaine County was listed in “severe” drought, NOAA’s third tier, while Sun Valley north to Trail Creek Summit was listed in “extreme drought,” its fourth, or second-worst, tier. Much of the county shifted into NOAA’s “exceptional,” or worst, drought tier last June.

On Dec. 31, the agency released its national winter drought outlook for January through March. According to that report, drought improvement is expected over the next few months in most of Oregon, Montana and Idaho as well as southern Washington and northern California.

In Idaho, NOAA expects to see drought listings removed by March in portions of the state, including southern Blaine County, eastern Custer County, Butte County, Clark County and much of eastern Idaho and the Panhandle. Meanwhile, drought should “remain but improve” in south-central Idaho and most of Blaine County.

Most of Idaho's mountains were their median snow water equivalent on Jan. 10. 

Conversely, NOAA expects drought will persist in most of Nevada, Colorado, Utah, New Mexico and Oklahoma and develop across the southeastern U.S. from Texas to Florida, according to the Dec. 31 report.

The agency also released a precipitation outlook for January through March forecasting “equal chances” of above-normal or below-normal precipitation in south-central Idaho, “likely above normal” precipitation in Stanley, Challis and northern Custer County and “above normal” precipitation in northern Idaho.

Snowpack totals continued to stand strong in the Wood River Valley this week. On Tuesday, the area’s six SNOTEL stations recorded 13.4 inches of accumulated precipitation since the start of the water year, about 132% of average.

The six SNOTEL stations also placed the Wood River Valley’s average snow-water equivalent—or theoretical depth of water that would result from melted snowpack—at 141% of normal, indicating the possibility of above-average runoff in the spring if precipitation trends continue.

Snow-water equivalent totals were highest at the Galena Summit SNOTEL site, which recorded 15.5 inches, or 155% of normal snowpack, on Tuesday.

During a Thursday presentation on current mountain snowpack conditions, hydrologist Danny Tappa of the NRCS-Idaho Snow Survey said that snowpack “is about a month ahead of schedule” in the Big Wood Basin, at 72% of its median annual peak snowpack of 15.1 inches, but those percentages will continue to drop every day the region does not get snow.

“We’re not out of the woods yet,” Tappa said. “We could still see below-normal snowpack by the end of winter, depending on weather.”

For now, current high snowpack levels are acting as a “buffer” against future dry weather, he said.

“With a couple weeks of dry weather in front of us looking likely we can kind of anticipate that these really healthy snowpack numbers will start to come down before hopefully we get some active weather near the end of the month.

“But with such a great start, we kind of have this buffer built in where we could have a couple of of dry weeks and it won’t be the end of the world.” 

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