Headline:
Flash Flood Warning issued July 17 at 7:17PM MDT until July 17 at 8:15PM MDT by NWS Boise ID
Event:
Flash Flood Warning
Urgency:
Immediate
Effective:
July 17, 2026 - 6:17pm
Expires:
July 17, 2026 - 7:15pm
Description:
At 717 PM MDT, the public reported thunderstorms producing heavy
rain over the Wapiti Burn Area. Between 0.5 and 1.5 inches of rain
have fallen. Flash flooding is already occurring.
Excessive rainfall over the burn scar has resulted in debris flows
moving through drainages in the area. Debris flows can consist of
rock, mud, vegetation and other loose materials.
HAZARD...Life threatening flash flooding and debris flows in and
around the Wapiti Fire Burn Scar.
SOURCE...Public reported debris flows blocking roads in the
Grandjean area.
IMPACT...Life threatening flash flooding and debris flows in and
around the Wapiti Fire Burn Scar will impact Grandjean
Road and Highway 21 from east of Lowman to Banner
Summit.
Some locations that will experience flash flooding include...
Grandjean and Warm Springs Guard Station.
Instruction:
This is a life threatening situation. Heavy rainfall will cause
extensive and severe flash flooding of creeks...streams...and
ditches in the Wapiti Burn Area. Severe debris flows can also be
anticipated across roads. Roads and driveways may be washed away in
places. If you encounter flood waters...climb to safety.
Area Description:
Boise, ID
Forcast Office:
NWS Boise ID
Sender: