Weekly conditions update — 6/15/2026:
– Scattered showers early last week were not enough to keep water year precipitation from dropping to 93% of average for the date.
– Snow has melted out at nearly all SNOTEL sites, with only the Two Ocean Plateau site holding 5.3 inches of SWE, compared to 13.4 inches on average.
– Streamflow in the tributaries has receded quickly over the past week, with most gages reporting streamflow at 30-70% of average for the date.
– Jackson Lake is 95% full with outflow remaining around 4,500 cfs. Reservoir storage has declined by 22,400 acre-feet over the past week. Surface water elevation is still well-above boat ramp elevations, but rapid drop in storage levels may affect access to Colter Bay by mid-to-late July. Reclamation has cited 1992 as a potential year for comparison.
– Palisades physically filled an additional 28,000 acre-feet over the past week due to remaining snowmelt moving through rivers and Jackson releases. The reservoir is currently 42% full and outflow has ranged from 10,400-12,000 cfs over the past week.
– Cooler air temperatures over the past week have slowed the increase in daily maximum stream water temperatures. All monitoring locations remain below Wyoming Game and Fish advisory levels.