The Wind River Basin only received 75 percent of its median precipitation during the month of March, according to this month’s Wyoming Water Supply Outlook from the Natural Resources Conservation Service.
Basin precipitation is at 90 percent of median for the entire water year, however, and local reservoir storage is close to 105 percent of median overall.
Plus, streamflow volumes due to snowmelt runoff in the Wind River Basin are expected to be among the highest in the state – though still below median at 88 percent.
Runoff rate
The snowmelt runoff rate will be lower because warmer-than-average temperatures have caused lower-elevation snowpack to become “ripe,” or “water-laden,” about a month earlier than usual, leading to water loss through percolation, evaporation, and groundwater recharge, NRCS hydrologist Jim Fahey said in his report.
The same conditions indicate there is a “good chance for an earlier than normal runoff,” he said, though he noted that “there is still much uncertainty in the eventual snowmelt runoff volumes due to the uncertainty of the timing and the amount of spring precipitation.”
“Many locations along east of the Continental Divide receive a great percentage of their annual precipitation during mid-March into early June,” Fahey said, including the Wind River Basin.
Forecasts show the weather will be drier and hotter than normal from April through July in Fremont County, however, and the U.S. Drought Monitor forecasts moderate to severe drought for the Wind River Basin this year, though conditions have improved compared to 2021.
Fahey said any changes in drought conditions will be “totally dependent on the amount of spring precipitation (and) temperature trends.”
Fahey’s Wyoming Basin and Water Supply Outlook Report is available here.