#Snowpack news:

Westwide SNOTEL basin-filled map January 11, 2020 via the NRCS.

From The Vail Daily (Randy Wyrick):

In the Colorado River Basin — Eagle County and the surrounding region — the snowpack is 110% of normal.

Statewide, snowpacks range between 104% and 129% of normal, according to NRCS data. The statewide snowpack is 119% of normal…

The water year begins in October, so things started dry and got wetter as winter set in. That means the water year’s actual precipitation is a little low, but winter storms are piling up the snowpack, according to the data…

Similar to the 2019 water year, which started in Oct. 2018, precipitation patterns and month-to-month snow accumulations have varied widely.

The 2020 water year started in October 2019 amid a late summer dry spell in southern Colorado. The northern basins — Eagle County and the surrounding region — were blessed with above-normal precipitation beginning in October and running through December with several snowstorms.

That means in our region, streamflows are also healthy so far this winter, with water supplies at or near average. Weather and precipitation patterns vary from region to region across Colorado, the NRCS report states.

In the Arkansas Basin, the water supply is forecast at 104% of normal. On the low end, the Gunnison and combined San Miguel, Dolores, Animas, and San Juan Basins are facing a water supply forecast at 88% of normal…

Across Colorado, 90% of the state’s water supply is forecast to hit between 85% and 115% percent of their average volumes, Wetlaufer said. Statewide reservoir storage is 106% of average, Wetlaufer said.

From The Mountain Mail (D.J. DeJong):

The U.S. Department of Agriculture Natural Resources Conservation Service reported early-season snow accumulations are encouraging for an ample water supply in the current water year in the Jan. 1 Colorado Water Supply Outlook Report.

Generous snowfall in October, November and December brought every major river basin above normal snowpack.

The Arkansas River Basin stands at 130 percent of median following two December storm cycles that added several inches of snow water to mountain snowpacks.

Statewide, the snowpack stands at 119 percent of median for the current water year, which began Oct. 1…

Reservoir storage varies across the state, but as a whole sits at about 106 percent of average.

Currently the Arkansas River Basin storage is below average at 98 percent.

The Upper Rio Grande Basin is also below average at 86 percent.

Storage in the other major basins ranges from 104-124 percent of average…

The average of forecasts in the Arkansas Basin is 104 percent of normal volumes, which is on the high end of basin forecasts.

From Drought.gov:

Current Situation and Impacts in the West
January 9, 2020

The large scale spatial pattern of snow water equivalent (SWE) anomalies in the Lower 48 has not changed much since our last update in early December: the Pacific Northwest generally remains below normal with a gradient to above normal as you move southeast into the Four Corners. However, the magnitude of these anomalies has changed significantly due a series of storms bringing above normal precipitation (for the past three weeks) to the Washington Cascades and a drying trend to the Sierra Nevada and Intermountain West. The core of the worst snow drought conditions has now shifted from the Washington Cascades to the central and northern Oregon Cascades. For HUC-6 Basins the Willamette Basin in Oregon currently has the lowest snowpack at 37% of median SWE while Washington Basins has improved to 55-75% of median. As of January 6 there are now no stations reporting record low SWE and only four stations in the Pacific Northwest reporting 2nd lowest SWE on record with one in Oregon, two in Wasington, and one in Montana.

Despite large improvements in precipitation deficits in the Washington Cascades, SWE gains were limited at lower elevations due to warm temperatures and rain instead of snow for much of December. Alpine Meadows SNOTEL, on the west slope of the Washington Cascades at 3500’ elevation, recorded 34.1” of precipitation between December 9 and January with only 11.5” of SWE gains. The most recent storms over the past week have brought colder temperatures and more snow accumulation at lower elevations compared to mid-December storms.

The poleward shift in the storm track has led to a drying trend south of the Cascades. Major storms in the Sierra Nevada have been absent since mid-December and many locations have fallen to near-to-slightly below normal SWE for this time of year. Small SWE losses have even occurred at some locations in the past week. At the Central Sierra Snow Lab, near Donner Pass California, SWE has declined from 13” on December to 12” on January 7 with 87% of median SWE. Overall, the Sierra is still in good shape with the Walker River Basin being the only HUC-6 below normal at 90% of median SWE.

Snowpack in south-central Alaska remain below normal with Kenai Peninsula and Prince William Sound HUC-6 basins at 56% and 50% of median SWE, respectively. In southeast Alaska there is only one station with long enough records to computes normals: Long Lake currently sits at 91% of median SWE. The few stations in the interior of Alaska currently reporting data all indicate above normal snowpack.

USDA Natural Resources Conservation Service (NRCS) percent of 1981-2010 median snow water equivalent (SWE) over the western U.S.
USDA Natural Resources Conservation Service (NRCS) percent of 1981-2010 average precipitation over the western U.S. for the period December 16, 2019-January 5, 2020. Only stations with at least 20-years of data are included in the station averages. For an interactive version of this map please visit NRCS
University of Idaho’s gridded meteorological data (gridMET) mean temperature difference from the 1981-2010 average for the period December 13, 2019-January 3, 2020. For an interactive version of this map please visit Climate Engine.

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