Thunderstorms Disrupt Seattle Weather and Airport Operations Thursday Morning

Thunderstorms with lightning rolled through the Seattle region Thursday morning, triggering flight delays at Sea-Tac International Airport and delivering heavy rainfall to portions of western Washington. The system was expected to clear by afternoon, with temperatures cooling afterward. The disturbance arrived around 10 a.m. in downtown Seattle, bringing thunder and lightning strikes that disrupted the morning commute across the region.

Airport Impact and Rainfall Distribution

Seattle-Tacoma International Airport experienced significant disruption as departures faced average delays of approximately 45 minutes by 9:45 a.m., according to Federal Aviation Administration data. The heaviest precipitation fell over the Olympic Peninsula, southwest Washington, and coastal ocean beaches through the early afternoon hours. Residents reported dramatic conditions, with car alarms triggered by the intensity of the lightning strikes in neighborhoods like lower Queen Anne.

The precipitation pattern shifted northward after midday, with rain breaking apart and moving toward Whidbey Island, the San Juan Islands, Port Angeles, and Forks. Brief additional showers remained possible around Seattle, Bellevue, Tacoma, and Kirkland during afternoon hours. Bellingham and Mount Vernon faced continued shower activity into early evening, while Seattle proper and the Cascade Mountains transitioned to drier conditions.

Weather Outlook and Temperature Trend

Overnight conditions featured broken cloud cover with possible isolated showers near Stevens Pass and Okanogan County, where lightning activity could persist through Friday morning. The system responsible for the disruption—an upper-level low pressure area—moved northward into British Columbia, allowing more settled weather to develop. Morning clouds followed by afternoon sunshine are expected to dominate the pattern for several days, with an improving weekend forecast.

A warming trend develops early next week as a heat ridge expands westward, with temperatures approaching 90 degrees across western Washington. The persistence of this warming depends on whether additional low-pressure systems from the Pacific and Canadian regions can move inland to counteract the high-pressure influence over the region.