Wyoming Water Supply Outlook--April 9, 2018

Extreme Heat Across the Southern U.S.; Flash Flooding Threats in the Mid-Atlantic, Northeast, and Four Corners Region

Dangerous and extreme heat will remain across portions of the southern U.S. this week. Heavy rainfall may bring significant flash flooding across portions of the Mid-Atlantic and Northeast through the night, and additional flash flooding concerns across New England on Wednesday. Monsoonal thunderstorms will bring a flash flood risk to the Four Corners region, especially in burn scar areas Read More >

HIGHLIGHTS

…Wyoming March 2018 precipitation was 100 to 110 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 (100 to 110 percent) snowmelt streamflow volumes are still expected across Wyoming during the upcoming snowmelt runoff season…

…Wyoming reservoir storages are at 110 to 120 percent of average for April…

SYNOPSIS

March 2018 precipitation totals across Wyoming were 100 to 110 percent of average. Precipitation numbers varied between 142 percent of normal over the Snake River Drainage (western Wyoming) to near 68 percent of average over the Clarks Fork/Shoshone River Basin (northwestern Wyoming). Current water year (October 2017 - March 2018) precipitation across Wyoming is averaging 100 to 110 percent of average.

Mountain snowpack across Wyoming remained at 105 to 115 percent of median by early April. Snowpack "water" numbers and/or SWEs continue to be the highest across basins in northwest to north central Wyoming—varying between 120 to 155 percent of median. SWEs across basins in southern Wyoming were at 75 to 100 percent of median.

Near normal (100 to 110 percent) snowmelt streamflow volumes are still expected across Wyoming during the upcoming snowmelt runoff season. Above average (>120 percent) streamflow volumes are forecasted across portions of the Wind, Bighorn, Shoshone, Upper Green, and Upper Yellowstone Watersheds. The Tongue, Lower Green, Upper North Platte, and Little Snake Basins are still expected to have below to near normal streamflow volumes during the upcoming snowmelt runoff season.

Reservoir storages across Wyoming remained above average at 110 to 120 percent for April.

The latest Wyoming water supply outlook graphic: