National Weather Service United States Department of Commerce

 

HIGHLIGHTS:

 

…Wyoming April 2018 precipitation was 95 to 105 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... 

…Overall, near normal (95 to 105 percent) snowmelt streamflow volumes are still expected across Wyoming during the upcoming snowmelt runoff season…

…Wyoming reservoir storages are at 105 to 115 percent of average for May…

 

SYNOPSIS:

 

April 2018 precipitation totals across Wyoming were 95 to 105 percent of average. Precipitation numbers varied between 171 percent of normal over the Snake River Drainage (western Wyoming) to near 65 percent of average over the Laramie River Basin (southeastern Wyoming). Current water year (October 2017 - April 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 May.  Snowpack "water" numbers and/or SWEs continue to be the highest across basins in northwest to north central Wyoming—varying between 120 to 160 percent of median.  SWEs across basins in southern Wyoming were at 65 to 90 percent of median. 

Overall, near normal (95 to 105 percent) snowmelt streamflow volumes are still expected across Wyoming during the upcoming snowmelt runoff season.  Above average (>130 percent) streamflow volumes are forecasted across portions of the Wind, Shoshone, Snake, and Upper Yellowstone Watersheds.  The Tongue, Lower Green, Upper North Platte, and Little Snake Basins are still expected to have below normal streamflow volumes during the upcoming snowmelt runoff season.

Reservoirs storages across Wyoming remained above average at 110 to 120 percent for May. 

 

The latest Wyoming water supply outlook graphic: