Riverton, Wyoming – Above-normal heat and a surge in mountain snowmelt could trigger flooding across central and western Wyoming this weekend, with thunderstorms adding to the risk by Sunday afternoon.
According to the National Weather Service in Riverton, daytime highs may reach 90°F on Sunday — the warmest of the year — accelerating snowmelt from elevations above 9,500 feet. A Hydrologic Outlook warns that this runoff could swell creeks and small streams through Monday, especially near the Wind River, Salt River, and Bighorn Mountain foothills.
Strong storms are possible Sunday in the northwestern part of the state, adding a flash flood risk to already rising water levels. Minor flooding is likely where snowpack remains in shaded or high-elevation terrain, and areas like the Upper Green and South Lincoln counties should remain alert.
Travelers should avoid flooded roads, monitor local advisories, and secure belongings near creeks and rivers. Sunday night through Monday may bring up to an 80% chance of showers and thunderstorms, with cooler, wetter weather continuing into Tuesday.
Warnings remain in effect through Monday night, with additional alerts possible as conditions evolve.
