Wyoming Water Supply Outlook--March 11, 2020

Back-to-Back Pacific Storms to Impact the West Coast; Heavy Snow in the Central Appalachians

Back-to-back powerful Pacific storm systems to impact the Pacific Northwest and northern California through the end of this week with heavy rain, flooding, strong winds, and higher elevation mountain snow. A strong, long-duration atmospheric river will accompany the Pacific storms, bringing excessive rainfall and flash flooding to southwest Oregon and northwest California through the week. Read More >

HIGHLIGHTS:

…Wyoming February 2020 precipitation was 130 to 145 percent of average...

...Current water year precipitation is averaging 100 to 110 percent of normal across Wyoming…

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

…Near normal snowmelt streamflow volumes are still expected across several major basins in Wyoming…

…Wyoming reservoirs are averaging 75 to 80 percent of capacity in early March…

SYNOPSIS:

February 2020 precipitation totals across Wyoming were 130 to 145 percent of average. Precipitation numbers varied between 230 percent of normal over the Tongue River Drainage (north central Wyoming) to near 90 percent of average over the Upper Bear and Lower Green Basins (southwest Wyoming). Current water year (October 2019 - February 2020) precipitation across Wyoming was 100 to 110 percent of average.

Mountain snowpack across Wyoming was 105 to 115 percent of median by early March. Snowpack "water" numbers and/or SWEs were the highest across basins in north central-east central Wyoming (Big Horn & Laramie Mountains)—varying between 120 to 135 percent of median. SWEs across basins in south central Wyoming (Sweetwater Basin) were 70 to 80 percent of median.

Near normal (95 to 110 percent) snowmelt streamflow volumes are expected across several major basins in Wyoming. Above average snowmelt streamflow volumes are expected across a majority of the Laramie, Upper North Platte, and Powder River 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 March. Reservoir storages across Wyoming are above average at 120 to 130 percent for March.

The latest Wyoming water supply outlook graphic:

Back-to-Back Pacific Storms to Impact the West Coast; Heavy Snow in the Central Appalachians

Wyoming Water Supply Outlook--March 11, 2020

HIGHLIGHTS:

SYNOPSIS:

Wyoming Water Supply Briefing: