An active and potentially dangerous weather pattern is developing across the Treasure Valley and central Idaho mountains as deep monsoon moisture surges northward, bringing the threat of dry lightning, gusty outflow winds, and heavy rainfall through the weekend.
Red Flag Warning and a Flash Flood Watch along with cooler temperatures in Scott Dorval's video forecast
Flash Flood Watch: Central Idaho Burn Scars
A Flash Flood Watch has been issued for the Wapiti Burn Area as deep monsoon moisture is expected to peak Friday afternoon and evening. Multiple other burn scars across the region are also being monitored for elevated flash flood risk through Saturday, including the Claremont Fire, Big Grass Fire, Tartar Fire, Fox Fire, and Colman Creek Fire burn scars.
Moisture values will climb toward the 80th to 95th percentile Friday, with the strongest moisture advection and dynamic forcing focused over central Idaho. As the atmospheric column saturates, the main hazard will transition from dry lightning and gusty winds to localized heavy rain. Flash flooding and debris flows will be a significant concern Friday afternoon and evening, particularly over steep terrain and recent burn scars.
Anyone planning to be in the central Idaho mountains Friday through Saturday should monitor conditions closely, be prepared to move to higher ground if heavy rain develops, and avoid camping or hiking in or near burn scar areas. Check weather.gov/boi for the latest Flash Flood Watches and Warnings.
Fire Weather Concerns for the Treasure Valley
The Treasure Valley and surrounding areas face elevated fire weather concerns tonight and Friday as dry lightning and gusty outflow winds accompany the initial wave of thunderstorms. The lower boundary layer will remain dry initially, meaning lightning will strike dry fuels without the benefit of wetting rain. Strong, localized outflow wind gusts up to 45 mph are possible with the stronger storms. Given receptive fuels and dry lightning potential, fire weather risks remain elevated across southwest Idaho.
Residents should be aware of current fire restrictions, avoid any activities that could spark a fire, and have an evacuation plan in case of new fire starts near their area.
Weekend Outlook
Saturday will continue the active pattern with a 40 percent chance of afternoon showers and thunderstorms. The flash flood risk for central Idaho burn scars will persist through Saturday afternoon as moisture values remain high. Temperatures will remain around 5 degrees below seasonal averages Friday and Saturday, with highs in the upper 80s providing a welcome break from the recent heat.
Sunday will bring a return to warm and mostly dry conditions as a ridge of high pressure builds back into the region, with highs climbing back to near 91 degrees. A quick-moving trough will bring cooler air and increased chances of showers and thunderstorms Tuesday into early Wednesday before the pattern becomes uncertain later in the week.
Tonight
A 30 percent chance of showers and thunderstorms, mainly after midnight. Mostly cloudy, with a low around 61. SE breeze 5-10
Friday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, then gradually becoming sunny, with a high near 87. Light wind.
Friday Night
A 20 percent chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 61. Light wind.
Saturday
A 40 percent chance of showers and thunderstorms, mainly after noon. Partly sunny, with a high near 89. Light wind.
Saturday Night
A 30 percent chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 61.
Sunday
Sunny and hot, with a high near 91.
Sunday Night
Partly cloudy, with a low around 62.
Monday
Partly sunny and hot, with a high near 91.
Monday Night
Mostly cloudy, with a low around 61.
Tuesday
Mostly sunny, with a high near 88.
Tuesday Night
Partly cloudy, with a low around 59.
Wednesday
Mostly sunny, with a high near 86.
Wednesday Night
Partly cloudy, with a low around 58.
Thursday
Mostly sunny, with a high near 88.
