Heat advisory issued for much of western Washington over Seafair weekend

There will be sunny skies this Seafair weekend as a heat advisory has been issued for much of western Washington.

Saturday morning temperatures will start in the 50s and quickly rise into the 70s and 80s in the afternoon.

Chief meteorologist Morgan Palmer said to expect temperatures in the mid-80s along the shores of Lake Washington by mid-afternoon, although with a pleasant northerly breeze.

Nothing will keep the Blue Angels and other aerial performers from showing off the full range of their sky acrobatics.

Some areas near the Cascades in Pierce County and parts of Thurston, Lewis and Mason counties could reach 90 degrees or very close to that by late afternoon.

For Sunday and Monday, expect hotter temperatures as cool Pacific waters exert less influence and high pressure aloft strengthens.

Highs will be in the upper 80s for Seattle with some low 90s in hotter spots east and south of the city. Morning lows will be in the 50s to lower 60s. This is not on the same level as the last heat wave, but will still be uncomfortable for non-air-conditioned homes.

Some haze and smoke from fires in British Columbia and east of the Cascades could affect the region starting Saturday night into Sunday; however, air quality is not expected to be significantly impacted at the surface.

By Tuesday, we’ll have the heat back off a bit with highs back in the 70s to mid-80s. More onshore flow and a weak trough of low pressure moving into the region Wednesday will bring more clouds, highs in the 70s and a slight chance of rain. There could also be some thunderstorms in the Cascades and east of the mountains around mid-week, increasing the threat for lightning-caused fires.

Beyond mid-week, Palmer expects temperatures to warm a bit again. The eight-14 day outlook for the mid-month time period suggests continued warmer-than-normal conditions across the Pacific Northwest. Fire danger will continue to increase.