The U.S. National Weather Service has issued a red flag warning for parts of the Olympic Mountains and Cascades from Thursday afternoon through 9 p.m. Forecasters expect isolated and, in some areas, more widespread thunderstorms, which may bring wind gusts of 20–30 mph (approximately 32–48 km/h). Such conditions can rapidly spread existing fires and spark new ones: lightning can ignite dry vegetation, while wind can carry the flames.
Seattle meteorologist Dev McMillian noted that unusually low snowpack last winter set the stage for an especially dangerous fire season in the mountains. Much of eastern Washington has already received similar warnings several times this month; fires have destroyed hundreds of homes and burned hundreds of thousands of acres. Such warnings are far less common in the western part of the state, but a new wave of wildfire smoke reached Seattle on Wednesday evening, turning the sunset hazy and smoky.
Based on: WA wildfires: Red flag warning issued for Olympics, Cascades