Thunderstorm Wind in Adams County, Washington

A large tree was blown down at a golf course in Ritzville.

A ridge of high pressure over the region for the last few weeks was nudged east by a potent upper-level trough coming off the Eastern Pacific. The trough took on a strong negative tilt and passed through during peak heating. An east to west line of strong thunderstorms developed over Northern Oregon and tracked northward through Eastern Washington and Northern Idaho during the late afternoon and early evening. Additional storms continued to develop along the gust front which picked up momentum as it passed into the region into an inverted V environment. The outflow winds picked up dust through Northern Oregon and Southern Washington resulting in a damaging dust storm or haboob. Visibility along Interstate 90 was reduced below a quarter of a mile and numerous locations clocked winds between 50 and 60 mph resulting in isolated downed trees and power outages. Proactive measures were taken at the Grant County Fair hours before the storm hit with nearly 8000 people evacuated and the fair cancelled to ensure the safety of the staff and attendees. Reduced visibility from the dust led to multiple accidents in the Columbia Basin.