NWS Boise IDFF.W 0011September 18, 2026
Flash Flood Warning: Elmore, ID
The National Weather Service office in Boise issued a flash flood warning for Elmore in Idaho, which was in force until 2:00 p.m. local time on September 18. It was the 11th flash flood warning the NWS office in Boise issued in 2026. Idaho had 10 flash flood warnings in September 2026, against 3 in an average September of 2008-2025 (Idaho's flash flood warnings by year).
ExpiredWarning
In force for 2.2 hours; it has expired. The agency may have replaced it with a new notice.
The notice
- Issued by
- National Weather Service, Boise ID
- Area
- Elmore
- State
- Idaho
- Level
- Warning
- Issued
- 11:49 a.m. MDT, September 18, 2026
- Expires
- 2:00 p.m. MDT, September 18, 2026
- CAP severity, certainty, urgency
- Severe, Likely, Immediate
- VTEC event
- KBOI FF.W 0011
- Official source
- National Weather Service: the notice at its source
Source: National Weather Service: the notice at its source. AreaZine rebuilds this page from the agency's record; the agency's page is the one to act on. A U.S. Government work, in the public domain.
The notice as issued
FFWBOI The National Weather Service in Boise has issued a * Flash Flood Warning for... The MM115 HWY 20 burn scar in... Central Elmore County in southwestern Idaho... * Until 200 PM MDT. * At 1149 AM MDT, Doppler radar indicated thunderstorms producing heavy rain over the MM115 HWY 20 Burn Scar. The expected rainfall rate is 0.25 to 0.75 inches in 1 hour. Flash flooding is ongoing or expected to begin shortly. Excessive rainfall over the burn scar will result in debris flow. The debris flow can consist of rock, mud, vegetation and other loose materials. HAZARD...Flash flooding caused by thunderstorms in and around the MM115 HWY 20 Burn Scar. SOURCE...Radar indicated. IMPACT...Flooding of areas in and around the MM115 HWY 20 Burn Scar. * Some locations that will experience flash flooding include... Mainly rural areas of Central Elmore County.
What the agency told people to do
This is a life threatening situation. Heavy rainfall will cause extensive and severe flash flooding of creeks...streams...and ditches in the MM115 HWY 20 Burn Scar. 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.
Source: National Weather Service: the notice at its source. The text is the agency's, unedited. A U.S. Government work, in the public domain.