2017 Washington State Tornado Outbreak
Town Tornado.jpeg
A tornado going through Downtown Swellview, WA
Type: Tornado Outbreak
Active: April 8th, 2017
Duration of tornado outbreak1: 4 hours, 5 minutes.
Maximum rated tornado2: EF2 tornado
Highest winds Unknown
Tornadoes confirmed: 14
Damage: $1.6 million (2017 USD)
Injuries: 9
Fatalities: 0
Areas affected: Northwestern United States particularly Washington and North Central Oregon

1Time from first tornado to last tornado
2Most severe tornado damage; see Fujita scale

The 2017 Washington State Tornado Outbreak is a short and a minor outbreak involving tornadoes as well as hail and damaging winds in the state of Washington. The outbreak lasted for about 4 hours on April 8, 2017 and April 9, 2017. A total of 14 tornadoes touched down. The strongest tornado was a weak EF2 which hit a barn and destroyed crops. A weak EF1 tornado went though downtown Swellview, injuring two people. The highest tornadic winds were estimated at 115 mph (185 km/h). The highest straight line winds were at 55 mph (90 km/h) at Paradise, Washington. Washo and Sherman counties in Oregon received a Significant Weather Advisory. Thunderstorms there created a wind gust of 35 mph (55 km/h).

Meteorological Synopsis


Radar indicated thunderstorms from the Pacific moving into places like Seattle, Tacoma, and Everett. Note: The storm hasn't intensified at that time.

On April 4th, 2017, the Storm Prediction Center (SPC) issued a day four risk of severe thunderstorms in Washington State and Oregon. At first it was under a Marginal risk (or a chance for isolated thunderstorms that can be severe). Then on April 6th an area to the east of Seattle to Idaho was under a Slight risk (scatter severe storms). The next day had increased it to Enhanced (more numerous storms).

The severe threat started to come into play in the late morning hours of April 8th. A developing squall line was coming from the Pacific as a cold front pushed it along. A surface low developed in British Columbia and moved east, obtaining the moisture from the Pacific. This caused bow echos to form. Low-level winds and the cold front caused a one squall line to form over Seattle which produced hail just to the east of the city. Tacoma received some damaging winds clocking in 40 mph (65 km/h). Throughout the day, severe thunderstorms has even generated a few tornadoes. Another squall line developed causing more storms in Eastern Washington. As the storm system heads east, it passed Spokane and started to weaken and the storms became more isolated while going though Idaho.

Confirmed Tornadoes

14 11 2 1 0 0 0

Saturday, April 8, 2019 event

List of confirmed tornadoes
Duration (PST)
April 8
EF0 Edgewood, Washington 4:05 PM A few trees fell.
EF0 Skykomish, Washington 4:30 PM A brief tornado touched down. One person sustained non-life threatening injuries.
EF0 Near Darrington, Washington 4:35 PM Minor roof damage.
EF0 Near Glacier Peak 4:45 PM The park have to shelter everyone in a warehouse. One person was hit with a large branch hit her in the back of the head and was taken to the hospital in serious condition.
EF1 Near Bridgeport, Washington 5:00 PM A moderate EF1 tornado hit an area close to Bridgeport, downing powerlines and tossing a tree onto a car with no one in it.
EF0 N of Thorp, Washington 5:10 PM A trailer park was hit with a low-end EF0 tornado. Two people were hurt by this.
EF0 N of Trinidad and Quincy, Washington 5:45 PM Several trees fell and injured two people.
EF0 N of Vantage, Washington 6:45 PM This weak EF0 tornado hit a subdivision. Shingles were off of roofs and a few trees were knocked over.
EF0 E of Yakima, Washington 6:50 PM Powerlines were toppled causing power outages lasting until the next day.
EF0 Near Ames Lake, Washington 6:55 PM An isolated thunderstorm brought hail and a tornado in the Ames Lake community. Damage estimates totaled nearly $580,000.
EF0 Near Mccarteney, Washington 7:05 PM The same isolated thunderstorm that hit Ames Lake also spawned an EF0 by Tieton State Airport. A plane flipped over.
EF0 S of Toppenish, Washington 7:30 PM A dangerous squall line started to develop and it formed a moderately strong EF0. It crossed US 97 and State highway 22. Winds were estimated at 80 mph (130 km/h). Cars and truck parked in a ditch and after the tornado passed, they had trouble getting out of there.
EF1 Swellview, Washington 7:45 PM The same squall line that hit Toppenish also hit downtown Swellview and brought a low-end EF1 tornado. Winds were estimated at 90 mph (145 km/h). Businesses and stores were severely damaged. Lots of people reported shaking and soon ducked for cover. One man was picked up by the tornado and just as it was losing strength, it tossed the man into a house and going though the roof and onto a girl. Fortunately, The guy tossed and the girl in the house both sustained very minor injuries. Damage in Swellview topped $750,000.
EF2 W of Pomeroy, Washington 8:10 PM The final tornado of the small outbreak hit a barn and destroyed it. It was a low-end EF2 with winds estimated at 115 mph (185 km/h). The farmer's house sustained damage and he was injured. Crops were ruined and soon the farmer had to move.

Other Weather events

Washo and Sherman counties in North Central Oregon have received a Significant Weather Advisory. Gust were reported to be at 35 mph (55 km/h). A developing squall over Tacoma brought damaging winds and hail was reported in the nearby city of Fife. Seattle received some heavy rain leading to minor street flooding. Snow was reported in the Kootenay Region in British Columbia. A half an inch of snow fell onto the ground.

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