Wyoming Water Supply Outlook--April 9, 2019

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 March 2019 precipitation was 105 to 115 percent of average...

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

…Mountain snowpack across Wyoming is 100 to 110 percent of median...

…Near normal to slightly above normal snowmelt streamflow volumes are expected across several major basins in Wyoming…

…Total reservoir capacity across Wyoming continues to be 70 to 75 percent by early April…

QUICK SYNOPSIS:

March 2019 precipitation totals across Wyoming were 105 to 115 percent of average. Precipitation numbers varied between 170 percent of normal over the Sweetwater/Lower North Platte River Drainages (south central to east central Wyoming) to near 50 percent of average over the Tongue River Basin (north central Wyoming). Current water year (October 2018 - March 2019) precipitation across Wyoming continued to be 100 to 110 percent of average.

Mountain snowpack across Wyoming was 100 to 110 percent of median by early April. Snowpack "water" numbers and/or SWEs were the highest across basins in southeast and western Wyoming—varying between 110 to 125 percent of median. SWEs across basins in north central Wyoming were 70 to 90 percent of median.

Near normal to slightly above normal (95 to 105 percent) snowmelt streamflow volumes are still expected across several major basins across Wyoming. Above average snowmelt streamflow volumes are expected across the Shoshone, Upper Bear, Upper North Platte, and Laramie Watersheds. Several rivers and creeks along the Tongue, Powder, and Upper Green Basins are forecasted to have below normal streamflow volumes during the upcoming snowmelt season.

Total reservoir capacity across Wyoming continues to be 70 to 75 percent by early April. Reservoir storages across Wyoming remain above average at 105 to 115 percent for early April.

The latest Wyoming water supply outlook graphic: