Wyoming water supply outlook
by Jim Fahey, Wyoming NOAA hydrologist
February 9, 2017
- Wyoming January 2017 precipitation was 170 to 180 percent of average.
- Current water year precipitation is averaging 130 to 140 percent of normal across Wyoming.
- Mountain snowpack across Wyoming is 115 to 125 percent of median.
- Above normal snowmelt streamflow volumes are expected across most major basins in Wyoming.
- Wyoming reservoir storages are 115 to 125 percent of average for February.
January precipitation totals across Wyoming were 170 to 180 percent of average. Precipitation numbers varied between 270 percent of normal over the Upper Bear River Drainage (southwest Wyoming) to near 100 percent of normal over the Powder River Basin (northeast Wyoming). Current water year (October 2016 – January 2017) precipitation across Wyoming is 130 to 140 percent of average.
Mountain snowpack across Wyoming was 115 to 125 percent of median by early February. Snowpack "water" numbers and/or SWEs were the highest across basins in central through southwestern Wyoming—varying between 145 to 185 percent of median. SWEs across basins in northeastern Wyoming were 100 to 110 percent of median.
Above normal (125 to 135 percent) snowmelt streamflow volumes are expected across almost all major basins across Wyoming. Above to well above average streamflow volumes are expected across the Wind, Shoshone, Upper North Platte, Upper Green, and Sweetwater Watersheds. The Powder, Tongue, and Upper Yellowstone Drainages are forecasted to have below to near normal streamflow volumes during the upcoming snowmelt season.
Reservoirs storages across Wyoming remained above average at 115 to 125 percent for February.