Wyoming Water Supply Outlook--April 7, 2017

Areas of Unsettled Weather in the Northwest and Eastern U.S. Early This Week

A modest atmospheric river will continue to bring unsettled weather to the Northwest U.S. through at least midweek including heavy rains for the coastal ranges and accumulating snow for the higher elevations. Over the eastern U.S., periods of light to moderate rainfall will continue from the Mid-Atlantic southward with some mixed wintry precipitation over the Northeast U.S. over the next few days. Read More >

HIGHLIGHTS

…Wyoming March 2017 precipitation was 135 to 145 percent of average...

...Current water year precipitation continues to average 135 to 145 percent of normal across Wyoming…

…Mountain snowpack across Wyoming is 110 to 120 percent of median...

…Above to much above normal snowmelt streamflow volumes are still expected across most major basins in Wyoming…

…Wyoming reservoir storages are 125 to 135 percent of average for April…

SYNOPSIS

March precipitation totals across Wyoming were 135 to 145 percent of average. Precipitation numbers varied between near 255 percent of normal over the Wind River Drainage (central Wyoming) to near 65 percent of normal over the Little Snake River Basin (south central Wyoming). Current water year (October 2016 – March 2017) precipitation across Wyoming continues to be 135 to 145 percent of average.

Mountain snowpack across Wyoming was 110 to 120 percent of median by early April. Snowpack "water" numbers and/or SWEs were the highest across basins in central Wyoming (Wind, Upper Green, and Sweetwater)—varying between 165 to near 200 percent of median. SWEs across basins in eastern-southeastern Wyoming were 85 to near 100 percent of median.

Above to much above normal (160 to near 170 percent) snowmelt streamflow volumes continue to be expected across almost all major basins across Wyoming. Well above average snowmelt streamflow volumes are still expected across the Snake, Wind, Sweetwater, Shoshone, and Upper Green Watersheds. The Little Snake, Upper North Platte, and Tongue Drainages are forecasted to have slightly below to slight above normal streamflow volumes during the upcoming snowmelt season.

Reservoirs storages across Wyoming remained above average at 125 to 135 percent for April.

The latest Wyoming water supply outlook graphic: