A weather disturbance moving across the state Wednesday will bring just enough atmospheric lift, combined with mountainous terrain, to kick off some thunderstorms mainly after the noon hour.
The best chance for thunderstorms will be from about Mount Rainier northward through the Canadian border, and on the east slopes into northeast Washington by late afternoon and evening.
There is also a slight chance for a thunderstorm in the Olympics range too.
Tuesday's edition of the Futuretrack Lightning forecast model shows the best chance for lightning in these higher elevations, northeast through northeastern Washington and into British Columbia.
While there will be some rainfall with these thunderstorms, it will likely not be enough to mitigate the threat of new fire starts wherever lightning strikes.
Many fires in our state were sparked by an extreme lightning event in mid-July, and while these storms are not expected to be nearly as prolific producers of lightning, all locations in the Cascades, Olympics, and even lower-elevation spots are tinder-dry and ready to burn.
Trees that are struck by lightning can smolder for days or even weeks before conditions are right for fire to erupt and spread.
Those in the mountains or east of the Cascades should keep a watchful eye to the sky from late Wednesday morning through the evening, and again possibly on Thursday (though thunderstorm activity isn't expected to be as widespread).
In the lowlands, the main impact from this system will be more clouds and slightly cooler temperatures in the mid 70s in Seattle on Wednesday
There are signs that wildfire smoke will move into Western Washington from British Columbia on Wednesday evening through Thursday, and while air quality will likely only slowly get worse with time, increasingly hazy skies are likely.
Air quality could fall to "moderate" category or possibly worse west of the Cascades later Thursday into Friday, in the more pessimistic scenario.
As winds turn over the weekend, air quality should improve west of the Cascades. We'll be monitoring closely for any changes in that forecast on KIRO 7.