A grass fire that started before noon Saturday near Airway Heights had grown into a 3,500-acre urban firestorm by nightfall, jumping the Spokane River and burning into neighborhoods inside Spokane's city limits.
Its growth was almost linear in speed: 50 acres by 12:30 p.m., 100 acres twenty minutes later, 300 acres in the early afternoon, 500 acres by 2:08 p.m., and 1,300 acres by 2:58 p.m., according to fire officials cited by KHQ .
Out-of-state fire crews, including units from California, were dispatched to help local departments already stretched thin by the state's broader fire load.
The fire continued spreading through the Five Mile Prairie area and along West Strong Road overnight, well after dark, as crews worked to establish containment lines in high wind.
It is a category the National Weather Service uses only when extreme wind, heat and dryness combine to make fire behavior unusually difficult to predict or fight, and Friday was the first time it had ever been declared for the state, according to the KXLY Firewatch team.
A grass fire near Airway Heights grew to 3,500 acres in hours, jumping the Spokane River into city neighborhoods and prompting a statewide wildfire emergency, a burn ban through September, and Washington's first-ever "particularly dangerous situation" fire warning.