Ashton, ID Weather

Key Messages

- Flash Flood Watch for Local Burn Scars: A Flash Flood Watch is in effect for the Wapiti, Ohio, and Big Rock burn scars from late tonight through Friday, where incoming precipitation could trigger debris flows and rapid runoff.

- Widespread showers and storms this evening through most of the day Friday.

- Much colder Friday. Daytime temperatures will drop by around 20 degrees.

Discussion

Issued at 139 PM MDT Thu Oct 22 2026

The low pressure system over California will continue to move inland and lift northward today, then overhead on Friday before exiting the region on Saturday. Showers and thunderstorms will overspread the CWA late this afternoon and tonight into Friday morning. Precipitation will trend lighter moving into Friday evening and conclude for the entirety of the forecast area by early Saturday morning.

The 48-hour National Blend mean QPF has increased slightly, sitting at roughly an inch across much of the forecast area, with closer to 1.25 to 1.50 inches across the central mountains eastward into the Island Park region. The 10th percentile is around 0.25" to 0.50" for much of eastern Idaho and closer to 0.75" for the central mountains into the Island Park region. The 90th percentile has increased to 1.50 to 2 inches for most of east Idaho, with around 2 inches for the central mountains. The official WPC forecast continues to run on the dry end, still sitting between the 10th and 25th percentile with much of the area forecast to receive less than 0.75" with 1 inch to 1.25 inches across the high elevations of the central mountains and Montana Divide region. Thus, a large spread continues to reflect a broad range of model solutions.

The snowfall forecast remains consistent with most of the snow falling above 7000 feet and mainly across the central mountains. There will be a 20 degree or so drop in temps between Thursday and Friday and temperatures Saturday morning will start off below freezing for many, but precipitation will largely be concluded by that time.

Dry weather is likely over the weekend into early next week. Temperatures will be a touch below average over the weekend and return to seasonable levels for next week.

Aviation

Issued at 1131 AM MDT Thu Oct 22 2026

SHRA/ISOL TSRA chances increase through the afternoon, then East Idaho transitions to more widespread RA/SHRA during the overnight. TSRA will have the potential to produce wind gusts over 20kts this afternoon, otherwise winds remain light. As the precipitation becomes more widespread, expect CIGS to fall from VFR to MVFR with isolated pockets of IFR during the overnight. SHRA continue through the day Friday with cold temps and CIGS remaining MVFR.

Fire Weather

Issued at 102 AM MDT Thu Oct 22 2026

Isolated to scattered thunderstorms are expected today. Some gusts to 35 mph are possible near storms. Otherwise winds should remain light. The wetting rains should arrive tonight and continue into Friday.