Flash Flood in Washington
Every flash flood event the National Weather Service has filed in Washington, 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 Washington.
- 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
- 202
- Deaths
- 2
- Injuries
- 2
- Damage
- $20 million
Every year
The most significant
Ranked by deaths, injuries, damage and size together.
- Flash Flood and High Wind in Washington, December 14 to 15, 2006A strong Pacific Ocean rain and wind storm struck Washington on the night of Dec 14th through the morning of the 15th.
- Flash Flooding and Winter Storm in Washington, February 2 to 28, 1999Heavy snow of 6-15" each day was reported across portions of eastern Washington, especially the mountainous areas. Some sites included: Chewelah, Newport, Republic, Mazma and Lake Wenatchee.
- Flash Flood in Washington, July 12, 2001Three to five inches of rain caused a significant 100+ year flash flood over the higher terrain of northeast Okanogan County on the evening of July 12.
- Flash Flooding and Hail in Washington, July 5, 2006Severe thunderstorms resulted in extensive hail damage, flash flooding, and wind damage across portions of Chelan and Okanogan counties. Hail damage was very extensive across both counties with the apple crop hardest hit.
- Flash Flooding and Hail in Washington, July 6, 2006Severe thunderstorms led to extensive hail damage, as well as flash flooding across Okanogan county. The apple crop was hit hardest, with damage also done to the pear and cherry crop.
- Flash Flooding and Debris Flow in Washington, September 5 to 6, 2013An upper level low pressure system over western Oregon ejected a negatively tilted shortwave trough of lower pressure over the region during the evening hours of September 5th. Precipitable water values were twice the normal value for early September.
- Flash Flooding in Washington, May 26 to 27, 19985-6 inches of rain overnight. Highways washed out in and around Republic
- Flash Flooding and Debris Flow in Washington, July 20, 2012One of the most widespread severe weather events occurred across the Spokane County Warning Area on July 20th. Several days prior to the day of the event, a deep upper-level low slowly sagged down the Pacific Northwest Coastline.
- Flash Flooding and Wildfire in Washington, July 3 to 31, 1998funnel cloud sighted on the south side of Wilbur.
- Flash Flooding and Debris Flows in Washington, July 16 to 20, 2012A nearly stationary upper level low pressure area parked near Brookings, Oregon brought abundant moisture across eastern Washington. This combined with daytime heating to produce a few severe thunderstorms and locally heavy rainfall.
- Flash Flooding and Flooding in Washington, June 5, 2022Another round widespread stratiform rain showers impacted the Inland Northwest. With the ground already saturated from previous system, the rain began to impact the region quickly with three quarters to an inch of rain.
- Flash Flood and Debris Flows in Washington, August 10 to 11, 2013Moist, southerly flow ahead of an area of low pressure trickling northward along the Oregon Coast created a moist, unstable environment over Central Washington.
- Flash Flood in Washington, April 13, 2017A privately owned dam holding a small pond failed on April 13th causing a flash flood which heavily damaged a section of Highway 129 between Fields Spring State Park and the Grand Ronde River. A bridge across Rattlesnake Creek was also destroyed.
- Tornado and Flash Flooding in Washington, July 9 to 12, 2023A strong system moved through Eastern Washington and brought scattered thunderstorms. The main areas stretched along Highway 2 from Waterville Plateau to Northern Spokane County.
- Flash Flood and Flood in Washington, April 9 to 10, 2019Beginning on April 6th and continuing through April 10th a series of Pacific atmospheric rivers were directed into Oregon, southeast Washington and central Idaho saturating the ground with heavy rainfall.
- Flash Flooding in Washington, July 4, 2022Two bands of heavy rain impacted Okanogan county during the afternoon. Areas impacted included Northeast of Mazama and Conconully. Rainfall ranged from 0.5 to 0.9 for Mazama and 0.6 to 1.4 for Conconully.
- Flash Flooding and Hail in Washington, June 2 to 3, 2022A deep upper level low over the Gulf of Alaska pushed nearly 200% of normal precipitable water into the Inland Northwest. It generated widespread thunderstorm activity. The steering flow of the storms was slow. It allowed the storms to rain large amounts.
- Flash Flooding and Hail in Washington, June 11 to 30, 1997FLOODING IN OMAK AND MUDSLIDES ON SR97 IN OMAK
- Flash Flooding and Hail in Washington, June 5 to 28, 19981.05 inches of rain in 1 hour and 1/4 inch hail
- Flash Flooding and Hail in Washington, June 1, 2015A trof of low pressure sweeping around the edge of a low pressure system moving north along the Oregon and Washington Coast produced numerous thunderstorms that moved across Eastern Washington and Northern Idaho.
- Flash Flooding and Heavy Rain in Washington, July 28, 2010Slow moving thunderstorms containing very heavy rainfall led to flash flooding across portions of Central and Eastern Washington. The west side of Wenatchee was hardest hit as a very slow moving thunderstorm brought 0.85 inches of rain in 45 minutes.
- Flash Flooding in Washington, May 16 to 17, 2015Showers and thunderstorms, both slow moving and moving over the same locations, resulted in some flash flooding and debris flows in Eastern Washington.
- Flash Flood in Washington, August 18, 2004A persistent thunderstorm moved across the Colville area about 5 pm causing flash flooding and wind damage. One report had 2 1/2 inches of rain in 45 minutes. Numerous buildings were flooded including the local jail. Many trees were blown down.
- Flash Flood in Washington, September 19, 2010A thunderstorm containing very heavy rain led to a significant road washout just south of Tonasket on McLaughlin Canyon and Hardy Roads. McLaughlin Canyon Road was washed out 10 feet deep and 15 feet across. Hail to the size of dimes was also observed during the thunderstorm.
- Flash Flood in Washington, June 27, 1996A slow moving thunderstorm dropped nearly 3 inches of rain in 2 hrs near Grand Coulee Dam. Highway 155 was washed out in several places and several homeowners yards were filled with debris from the flooding.
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.