Flash Flood in Oregon
Every flash flood event the National Weather Service has filed in Oregon, year by year, with the most significant episodes. Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
The most significant on the map
The most significant flash flood episodes in Oregon.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The record
- Events
- 112
- Deaths
- 1
- Injuries
- 1
- Damage
- $1.9 million
Every year
The most significant
Ranked by deaths, injuries, damage and size together.
- Flash Flood in Oregon, August 12, 2014Heavy rain resulted in a rapid increase of water in the Sandy River. The sudden rush of water damaged a foot bridge as a group of people were walking across it. One of the hikers that fell into the water did not survive.
- Flash Flood and Flooding in Oregon, May 14 to 18, 2011An upper level low pressure system moved over the Pacific Northwest. Moist and unstable conditions ahead of the low triggered widespread thunderstorms with heavy rainfall and isolated large hail.
- Flash Flood in Oregon, July 18, 2002The Wallowa County Sheriff's Office confirmed a mudslide near the Blue Mountain Council Boy Scout Camp at the south end of Wallowa Lake. The mudslide destroyed a dining hall near the boy scout camp. The debri flow in the lake was several feet thick.
- Flash Flooding and Debris Flow in Oregon, July 16 to 20, 2012A nearly stationary upper level low pressure area parked near Brookings, Oregon brought abundant moisture across eastern Oregon. This combined with daytime heating to produce a few severe thunderstorms and locally heavy rainfall.
- Flash Flood in Oregon, September 8, 2017Heavy rain fell across the Rail Burn Scar resulting in flash flooding including debris flow.
- Flash Flooding and Hail in Oregon, April 23, 2012An upper level disturbance moving north on the back side of an upper level ridge combined with a very moist atmosphere to produce local severe thunderstorms and flooding.
- Flash Flood in Oregon, April 26, 2005A rupture in a retaining wall of a wastewater storage lagoon led to a dam failure which sent 77 million gallons of wastewater onto highway 207 south-southwest of Hermiston, washing out part of the road, and depositing several feet of silt on the road.
- Flash Flooding and Hail in Oregon, August 30, 2007A severe and wet thunderstorm fueled by monsoonal moisture struck south Ashland on the afternoon and evening of 08/30/2007. The severe hail associated with the storm was apparently short-lived and highly localized, but flooding and wind damage was more widespread.
- Flash Flood and Flood in Oregon, August 9, 2019A powerful upper storm system combined with modest low and mid level moisture to yield scattered strong to severe storms and flash flooding. Storms developed first across the higher terrain of central Oregon nearer the Cascades and adjacent Ochoco mountains.
- Flash Flood and Heavy Snow in Oregon, June 1 to 2, 2011Persistent showers with heavy rainfall of 1 to 2 inches produced flooding on Willow and Hinton Creeks. Snowfall amounts in inches include 15 miles southeast of Heppner (6.5), Arbuckle Snotel (10), Madison Butte Snotel (6).
- Flash Flood and Hail in Oregon, May 30 to 31, 2020A major severe weather event by Pacific Northwest standards occurred over central and northeast Oregon and southeast Washington on May 30th. A powerful upper level storm system moved across the area during the afternoon and evening helping to trigger severe thunderstorms.
- Flash Flooding and Dust Storm in Oregon, May 12 to 31, 1997A thunderstorm sent a 2-foot wall of water through several homes and fields soaking carpet and scattering silt over several hundered acres. The water also took out fences and caused damage to a road.
- Flash Flood and Hail in Oregon, August 8, 2019An approaching storm system combined with modest instability allowed for spotty strong to afternoon storms near the Cascades. The slow moving nature of the storms also lead to heavy rainfall and flooding in at least one area.
- Flash Flooding and Hail in Oregon, September 5, 2013Several reports of severe weather from wind damage, to large hail, and flash flooding hit portions of central and northeast Oregon on September 5th. The largest hail reported was 1.75 inches and the strongest estimated wind gust was 70 mph.
- Flash Flood and Flooding in Oregon, August 24 to 26, 2004A series of unseasonably strong Pacific frontal systems dumped heavy rain over the Pacific NW from August 21-26. Heaviest amounts were over the Northern Oregon Cascade Mountains, where 10 to 12 inches of rain fell.
- Flash Flood and Hail in Oregon, May 4, 2017A strong upper-level trough generated enough instability for a few severe thunderstorms to develop across NW Oregon.
- Flash Flood and Hail in Oregon, June 20 to 21, 2018An upper-level trough moved across the area from the southwest, generating strong thunderstorms which produced locally heavy rainfall, lightning, hail, and gusty winds.
- Flash Flood and Hail in Oregon, August 1, 1997.
- Flash Flooding and Hail in Oregon, June 29, 2004Mud slide across Hwy 26 north of Unity...see narrative for Idaho this date.
- Flash Flood and Hail in Oregon, June 26, 2017A disturbance, associated with subtropical moisture, caused thunderstorms producing large hail and severe wind gusts over portions of eastern Oregon and southeastern Washington. Also locally heavy rain and local flooding occurred with some storms.
- Flash Flood and Heavy Rain in Oregon, June 11 to 13, 2023A nearly stationary upper level low over the Four Corners region brought periods of heavy rain and thunderstorms over multiple days which caused localized urban flooding in Malheur County, OR.
- Flash Flood and Hail in Oregon, May 20 to 21, 2023Southwesterly flow aided by an approaching upper level trough facilitated another round of strong diurnal convection during the afternoon hours, starting the central Oregon and along the eastern Mountains before expanding northeastward.
- Flash Flooding and Hail in Oregon, May 25, 2018Persistent moist southwest flow continued into the 25th of May. Thunderstorms developed late morning and continued well into the evening. The storms produced locally heavy rain and some flooding. Also some hail occurred with the storms.
- Flash Flood and Damaging Wind in Oregon, July 30, 1998The John Day Airport reported a thunderstorm wind gust to 63 MPH. Small trees were blown down east of the town of John Day. Pea sized hail accumulated to three inches deep about five miles south of Prairie City.
- Flash Flooding in Oregon, February 16 to 17, 2004An Urban and Small Stream Flood Warning was issued for Oregon zones ORZ021/022/024 effective at the above listed times. No verifying reports were received, but heavy rains did occur and small streams were running high.
More
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.