Wyoming Water Supply Outlook--April 14, 2020

Arctic Air Bringing Cold Temperatures to the Eastern Half of the U.S.; Strong Clipper System Wednesday and Thursday

Arctic air will continue below normal temperatures across the eastern half of the U.S. through today. A strengthening clipper storm will track north of the Great Lakes midweek with a widespread snow and gusty to strong winds through the region and into the Northeast U.S. followed by some lake effect snow. Read More >

HIGHLIGHTS:

…Wyoming March 2020 precipitation was 80 to 90 percent of average...

...Current water year precipitation is averaging 95 to 105 percent of normal across Wyoming…

…Mountain snowpack across Wyoming is still 105 to 115 percent of median...

…Near normal (95 to 110 percent) snowmelt streamflow volumes are still expected across several major basins in Wyoming…

…Wyoming reservoirs continue to average 75 to 80 percent of capacity in early April…

SYNOPSIS:

March 2020 precipitation totals across Wyoming were 80 to 90 percent of average. Precipitation numbers varied between 145 percent of normal over the South Platte River (southeast Wyoming) and Upper Yellowstone (northwest Wyoming) Drainages ; to near 45 percent of average over the Big Horn and Tongue Basins (north central Wyoming). Current water year (October 2019 - March 2020) precipitation across Wyoming was 95 to 105 percent of average.

Mountain snowpack across Wyoming was 105 to 115 percent of median by early April. Snowpack "water" numbers and/or SWEs were the highest across basins in north central through western Wyoming—varying between 115 to 125 percent of median. SWEs across basins in south central Wyoming (Sweetwater Basin) and eastern Wyoming were 70 to 80 percent of median.

Near normal (95 to 110 percent) snowmelt streamflow volumes are still expected across several major basins in Wyoming. Above average snowmelt streamflow volumes are expected across portions of the Laramie, Upper North Platte, Powder, and Snake (Salt) Watersheds. The Sweetwater and Upper Green Basins as well as portions of the Little Wind River Drainage are still forecasted to have below normal streamflow volumes during the upcoming snowmelt season.

Wyoming reservoirs are averaging 75 to 80 percent of capacity in early April. Reservoir storages across Wyoming remained above average at 120 to 130 percent for April.

Current Wyoming Water Supply graphic: