Residents across western Washington should prepare for a combination of warm temperatures, possible thunderstorms and an elevated wildfire risk as weather conditions change later this week, according to the National Weather Service in Seattle.
Warm, mostly dry weather will continue through Wednesday, with widespread Minor HeatRisk across the region and localized Moderate HeatRisk possible in the Seattle and Tacoma metropolitan areas. Forecasters say there is a 50% to 90% chance of moderate heat conditions developing Wednesday in portions of the central Puget Sound region.
While temperatures will remain above normal, weather conditions are expected to become more unsettled beginning Wednesday afternoon, when isolated thunderstorms are possible along the Cascade crest, particularly near Mount Rainier. The National Weather Service estimates a 10% to 20% chance of thunderstorms in the Cascades Wednesday afternoon and evening.
The greatest concern arrives Wednesday night through Thursday night, when a Pacific weather system is expected to increase the likelihood of showers and thunderstorms across much of western Washington. Although forecasters say uncertainty remains regarding the exact timing, coverage and rainfall amounts, confidence has increased enough for the National Weather Service to issue a Fire Weather Watch for portions of the Cascades and Olympic Mountains.
If thunderstorms develop, they could produce dangerous lightning, gusty winds, small hail and brief periods of heavy rain. Lightning also could spark new wildfires because of the region’s ongoing dry conditions, particularly in forested areas. Outdoor recreationists and anyone planning activities later this week are encouraged to monitor changing weather conditions.
After a brief cooldown Thursday, warmer weather is expected to return over the weekend and into next week. Forecasters are monitoring the potential for another period of elevated heat Monday through Wednesday, with some interior communities facing a 15% to 40% chance of reaching Major HeatRisk levels by Tuesday and Wednesday.
The National Weather Service recommends residents stay hydrated, limit strenuous outdoor activities during the warmest part of the day, check on older adults and other vulnerable neighbors, and remain alert for changing weather conditions if traveling or recreating in the mountains.
