SEATTLE— The effects of a rapidly developing “bomb cyclone” hit the Seattle area Tuesday evening, killing at least one person and injuring two others, as winds of 50 to 75 miles per hour toppled trees in the region.

A woman was killed in Lynnwood when a tree fell into an encampment, according to South County Fire Department officials.

South of Seattle, two others were injured when a tree fell into their trailer in Maple Valley, Puget Sound Fire reported.

Two injured when tree fell on trailer in Maple Valley, Washington on November 19, 2024

(Puget Sound fire)

One person was quickly freed, but it took firefighters an hour to free the other resident, who was trapped in the mangled rubble. Both were taken to local hospitals, but their conditions were not provided.

Two injured when tree fell on trailer in Maple Valley, Washington on November 19, 2024

(Puget Sound fire)

According to the Seattle Fire Department, a driver was struck by a falling tree while driving in northeast Seattle. The person was released and is in stable condition, fire officials said. Crews there said several other trees near the intersection were down.

Wind gusts in the Cascade foothills just east of Seattle reached more than 75 miles per hour, fueled by a low-pressure center that underwent explosive development in just a few hours as it swirled off the coast of Washington.

Satellite image of bomb cyclone

(NOAA)

According to PowerOutage.US, it was estimated that more than 700,000 people in Western Washington had lost power. More than 100,000 of them were in the city of Seattle.

A wind gust reached 75 mph in the city of Enumclaw before the anemometer went dark, along with the rest of the city.

“The sound here is unreal!” said Anthony Concannon. “The wind in the trees and power lines is deafening.”

In Bellevue, the state’s fifth-most populous city, wind gusts of 55 mph sent firefighters rushing to help several neighborhoods reporting trees in homes.

“Trees are falling and falling on homes all over the city,” Bellevue fire officials said. ‘If you can, go to the lowest floor and stay away from windows. Don’t go outside if you can avoid it.’

State and local city officials said several major highways were blocked by falling trees and power lines, including portions of busy state Routes 18, 516 and 169. Just before midnight, a tree fell across four lanes of Interstate 405 in Bellevue.

Tree falls on house in Issaquah, WA

(East side fire and rescue)

“There are so many trees and power lines down, we would post the locations until the lights come on,” an exasperated Snohomish Regional Fire & Rescue posted on X.

Easterly gusts reached 60 miles per hour at Sea-Tac Airport, where rare easterly winds presented pilots with a challenging crosswind to navigate runways aligned with the persistent southerly winds the region normally endures.

Bomb cyclone lowers pressure by 66 millibars in 24 hours

The storm was caused by a historic storm that went from a harmless low-pressure trough into the strongest storm ever recorded in that part of the Pacific Ocean. Measurements showed that the storm’s pressure dropped by 66 millibars in 24 hours, eventually becoming a storm with a central pressure of 943 millibars – comparable to a major Category 4 hurricane. It easily qualified for the title “bomb cyclone”, given when a storm strengthens by approximately 24 millibars in 24 hours.

While the deep center of the storm remained hundreds of miles offshore, the storm’s location due west of the Washington coast, combined with cold, dense upper pressure in eastern Washington, created a huge pressure differential in the western half of the state.

Tree falls on house in Issaquah, WA

(East side fire and rescue)

Winds from eastern Washington were hitting the barrier created by the Cascade Mountains, but holes in the terrain along the mountain passes caused breaks in the barrier, allowing the wind to speed up and shoot through the passes like a hole in a balloon .

The winds devastated towns that were located along highway spurs and were gateways to popular hiking trails and ski resorts.

When the easterly winds reached the western edges of the Cascades and broke away from their mountain conquerors, they raced across the lowlands of Puget Sound, bringing with them rare easterly winds that overran the forested landscapes that had adapted to the region’s more common southerly winds. The result was widespread tree fall from north to south along the Puget Sound region.

Winds were expected to ease early Wednesday morning, allowing an extensive cleanup to begin.