Weather Blog

Thursday is 40-year anniversary of Washington's only deadly tornado

Thursday is 40-year anniversary of Washington's only deadly tornado

Washington and Oregon average about 1 or 2 tornadoes a year each, and usually what few we get are quite weak and do minimal damage.

But that was not the case 40 years ago today.

On April 5, 1972, a devastating F3 tornado struck the Vancouver, Washington area, killing 6 people and injuring 300. It is far, far and away the worst tornado in Pacific Northwest history, and really, no tornado event has ever come remotely close to matching it. In fact, it still stands today as the only deadly tornado in recorded Washington history. (Knock on wood.)

According to TornadoProject.com, there have been two other storms in Washington that rated an F3 -- one was the same date as the Vancouver tornado, but in Lincoln County. One person was injured there.

An F3 tornado also struck the Kent Valley on Dec. 12, 1969. One person was injured there as well. Finally, one tornado that touched down near LaCenter in Clark County on June 29, 1989 injured one person when their car was lifted six feet.

Those are the only tornadoes that have injured anyone in Washington since records have been kept in 1880.

In Oregon, there were reports of a tornado that killed three and injured 5 on June 14, 1888 near Lexington in Morrow County, and another one on June 3, 1894 in Grant County that killed three and injured 10. There have been no tornado-related deaths in Oregon since that 1894 tornado.

What Happened In Vancouver?

The National Weather Service in Portland has an excellent write-up on what happened that fateful day in 1972:

A very turbulent squall line moved northeast across Portland, causing scattered wind damage, broken tree limbs, and even uprooting some trees. Track of the strongest storm cell in the squall line was first indicated at Tigard where straight line winds unroofed a lumber warehouse at 12965 SW Pacific Highway, and its debris damaged five vehicles parked in a neighboring service station. High winds were experienced across the West Hills of Portland and tree limbs littered Hamilton Park. Passage of the storm cells across Portland caused a 0.12 inch pressure jump as recorded by the NWS Climatology Office in the Multnomah Building in downtown Portland. Straight line winds toppled several trees at the south edge of the Riverside Country Club just 1.4 miles southwest of the Columbia River's south bank.

The Portland/Vancouver tornado that developed from this storm fist touched down at the south edge of the Columbia River damaging four pleasure boat moorages in the 3300 to 3400 blocks of NE Marine Drive. About 50 cabin cruisers were either damaged or blown about by the wind as it damaged a dry dock, boat houses and dock shelters. The funnel was not observed locally because it was obscured by mud and flying debris. It was described as a clack mass, and several persons reported seeing water being drawn up into the cloud as the tornado moved one-half mile before crossing the Oregon-Washington state line in the middle of the Columbia River and continuing on to the Washington shore. Observers were unable to see across the Columbia River because of the water vapor.

The tornado continued its nine-mile total damage path across the east side of Vancouver to the Brush Prairie area. Six persons lost their lives while 300 persons were injured. The tornado caused five to six million dollars in property damage in Washington alone. The tornado was the most devastating tornado in Oregon's recorded weather history, dating back to 1871.

Additional wind damage in the Portland area included fallen trees on two homes in Lake Oswego, trees blocking sections of NE Glisan and Flanders and smashing two automobiles, and damaged telephone and power lines. Portland National Weather Service Office on 5421 NE Marine Drive (about 1 mile east of the tornado touchdown) recorded a sustained wind of 48 miles per hour from the south at 12:53 pm and gusts of 63 mph from the south at 12:52 pm. Here are more wind reports from the Portland area:

Wind Reports from the April 5 1972 Thunderstorm:
  • Portland, Morrison Bridge: South wind 48 mph, recorded at 1244 pm
  • 710 SW Viewpoint Drive (Vancouver): South wind 50 mph
  • Mt Scott (east Portland): South wind 82 mph
  • 2900 NE Marine Drive (Portland): Estimated West wind 40 to 60 mph
  • 3417 NE Marine Drive (Portland): South wind 40 to 50 mph before the storm hit, then South wind hit 120 mph before measuring equipment was damaged
  • 3737 NE Marine Drive (Portland): Southeast wind 80 mph

How rare are tornadoes here?

It used to be that Washington averaged just one tornado per year in the state, but factoring in more recent data, our official average is now up to two -- most likely helped by our 1997 season that had a record 14 tornadoes.

Still, tornadoes are typically very weak here, typically rating an EF0 or EF1 on the Enhanced Fujita Scale

Strong tornadoes need severe thunderstorms fed by large changes in temperature in the upper atmosphere. Severe thunderstorms typically need much colder air moving in aloft to make the air very unstable.

The so-called "Tornado Alley" in the Midwest is ripe for severe weather due to frequent battles between cold, arctic air marching south of out Canada colliding with very warm, moist air moving north from the Gulf of Mexico.

But in the Pacific Northwest, the cool waters of the Pacific Ocean are a great moderating force that keeps temperature changes from being too drastic, and thus tornadoes are quite rare.

What are more common here are what we call "cold core funnels"

They are different from typical devastating Midwest tornadoes in that these are spawned from non-severe storms and can occur when you get a tightly wrapped rush of rising air that can appear as a funnel.

They get their name from the usual pattern when you have a storm bringing much colder air into the higher altitudes -- a common occurrence around here in spring and fall.

Cold-core funnels rarely reach the ground, and if they do, are very weak. They are not all *that* rare with well-formed Convergence Zones -- especially in spring and autumn.

More tornado information:

Storm Prediction Center's Online Tornado FAQ

National Tornado Statistics

List of all tornadoes in Washington, 1950-2011

List of all tornadoes in Oregon, 1951-2011

List of all tornadoes in Washington State, broken down by county, 1880-2000