National Weather Service United States Department of Commerce

Severe Thunderstorm and Heavy Rainfall Potential Continues

A low pressure center tracking across the Great Lakes and its associated cold front extending across the Southern Plains will focus occasional showers and thunderstorms through tonight. A few of these thunderstorms may become severe alongside heavy rainfall that may cause flash flooding; Portions of the Southern Plains would be the greatest threat for these hazards through tonight. Read More >

HIGHLIGHTS:

…Wyoming April precipitation was 135 to 145 percent of average...

...Current water year precipitation increased to near 120 percent of normal across Wyoming…

…Mountain snowpack across Wyoming increased to 95 to 105 percent of median... 

Slightly below normal snowmelt streamflow volumes are expected as a whole across Wyoming...

…Wyoming reservoir storages increased to 115 to 125 percent of average for April...

Synopsis:

April precipitation totals across Wyoming were 135 to 145 percent of average. Precipitation numbers varied between 185 percent of normal over the Wind River Basin to near 65 percent of normal over the Upper Yellowstone Basin (northwestern Wyoming).  Current water year (October 2015 – April 2016) precipitation across Wyoming increased to near 120 percent of average.

Mountain snowpack across Wyoming remained to 95 to 105 percent of median by early May.  Snowpack "water" numbers and/or SWEs were the highest across basins in southern Wyoming—varying between 120 to 140 percent of median.  SWEs across the Snake and Upper Yellowstone   Watersheds varied between 75 to 85 percent of median.

Slightly below normal (90 to 95 percent) snowmelt streamflow volumes are expected across the state as a whole.  Above normal streamflow volumes are expected across a majority of the Wind River, the Upper North Platte, and the Laramie Watersheds.  The Upper Green, Snake, and Tongue River Basins are forecasted to have below normal streamflow volumes during the upcoming snowmelt season.

Reservoirs storages across Wyoming remained at 115 to 125 percent for May. 

The latest Wyoming water supply outlook graphic: