With warm and dry conditions, snowmelt has started at all elevations. Due to a shallow snowpack and early melt, agency forecasts of summer streamflow for the Snake River at Heise have dropped to 70-82% of normal. While a cool, wet spring can help, it is very likely that streamflow across the Snake River Headwaters will be below average this summer. Read on for a summary of current conditions.
· Peak SWE occurred 24 days earlier than normal on March 17th at only 86% of the median peak. Current SWE is 11.05 in and is the lowest for the date in the past 30 years.
· With average temperatures over the past month 3-6 °F above normal, snow has melted quickly and streamflow has increased. Many tributary gages are reporting all-time highs for the date due to early snowmelt.
· Jackson Lake continues to fill, with outflow remaining near 300 cfs. To meet downstream irrigation demand, Palisades outflow has increased to 7,500 cfs.
Data are from NRCS SNOTEL, US Drought Monitor, US Geological Survey, US Bureau of Reclamation, and Teton Conservation District.