Spring Runoff Outlook-March 9 2015

Wyoming Water Supply Outlook---issued March 9, 2015

…Wyoming February precipitation was nearly 110 percent of average...

...Current water year precipitation is averaging 90 to 95 percent of normal across Wyoming…

…Mountain snowpack across Wyoming continues to be 90 to 95 percent of average... 

…Below normal snowmelt streamflow volumes are expected across major basins in Wyoming...

…Wyoming carryover reservoir storages are 115 to 125 percent of average for March…

February precipitation totals across Wyoming were nearly 110 percent of average. Precipitation numbers varied between 200 percent of normal over the Wind River Basin to near 65 percent of normal over the Belle Fourche Drainage (Northeast Wyoming).  Current water year (October 2014 - February 2015) precipitation across Wyoming is nearly 95 percent of average.

Mountain snowpack across Wyoming was 90 to 95 percent of normal by early March.  Snowpack "water" numbers and/or SWEs were the highest across basins in north central Wyoming---varying between 105 to 125 percent of median.  SWEs across southern Wyoming continued to be the lowest at 75 to 95percent of median.

Below normal (85 to 95 percent) snowmelt streamflow volumes are expected across almost all major basins across Wyoming.  Slightly above average streamflow volumes are expected across the Yellowstone/Clarks Fork as well as portions of the Powder and Tongue River Drainages.  Several southern Wyoming basins—including the Sweetwater, the Little Snake,  and the Bear---are forecasted to have well below normal streamflow volumes during the upcoming snowmelt season.

Carryover reservoirs storages across Wyoming continue to be above average (greater than 115 percent) for March. 

The latest Wyoming water supply outlook graphic: