Wyoming precipitation down 30% from average; spring runoffs expected to be low By Brendan LaChance on January 11, 2021 Ice forms on the North Platte River on Monday, Dec. 28, 2020. (Dan Cepeda, Oil City) CASPER, Wyo. — With precipitation below average in Wyoming, spring runoffs are expected to be lower than usual this spring. “Spring runoff volumes are expected to be around 80% of normal for Wyoming,” Natural Resources Conservation Service Wyoming Hydrologist Jim Fahey said on Monday. The NRCS released their Wyoming Basin & Water Supply Outlook Report on Monday which states that precipitation across basins in the state was near 70% of average as of Jan. 1.