Severe · Flash Flood WarningThis alert has expired. It is kept for reference.

Flash Flood Warning issued September 18 at 5:47PM MDT until September 18

Affecting Boise, ID

In effect until: Sep 19, 2026, 2:15 AM

Boise, ID

Likely impact in Boise, ID; effects through 2:15 AM.

Get to higher ground now. Never drive through flooded roads.

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FFWBOI

The National Weather Service in Boise has issued a

* Flash Flood Warning for...
The Wapiti Burn Area in...
Northeastern Boise County in southwestern Idaho...

* Until 815 PM MDT.

* At 547 PM MDT, emergency management reported thunderstorms
producing heavy rain over the Wapiti Burn Area. Flash flooding is
ongoing or expected to begin shortly. Excessive rainfall over the
burn scar will result in debris flow moving through the High
Drainage Test. The debris flow 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...Emergency management reported debris on Idaho State
Highway 21 between mileposts 103 and 105.

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.

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Alert data: U.S. National Weather Service / NOAA · Translation: WeatherTranslate™

Flash Flood Warning issued September 18 at 5:47PM MDT until September 18

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