SEATTLE — With some sinking air nearer the Cascades, the hottest locations Friday will likely be nearer the mountains in places like Monroe, North Bend and Enumclaw, where highs could reach the mid 90s. A Heat Advisory has been issued for these locations and it also stretches into all of Thurston and Lewis counties.
This round of heat will not be as extreme as the record-breaking temperatures in June.
For Seattle and points closer to Puget Sound, we’re looking at highs in the mid 80s to lower 90s after morning lows in the 50s to low 60s. Seattle should be around 93 degrees Friday.
East of the mountains, temperatures will commonly be over 100 degrees.
By Friday afternoon, expect some showers and thunderstorms to bubble up over the South Cascades, mainly south of I-90. Of course, any lightning strikes will pose the risk of fire starts, though these cells are likely to produce some rain, too, so that’s at least a little mitigating factor.
One more issue starting Friday and continuing into the weekend: some elevated wildfire smoke from down south will cause some hazy skies but it is not expected to cause any problems with lowland air quality for Western Washington. From the Cascades east, some degradation of air quality can be expected.
By Saturday, we’ll start some very subtle cooling in Western Washington, but the Cascades thunderstorm threat will likely be even greater and be a problem for the entire Cascades range in our state and points east – particularly later in the day. Highs for Seattle and vicinity will be in the upper 80s.
There is the slimmest of chances for a lowland rain shower or thunderstorm late Saturday, Saturday night and Sunday, but compared to how the data looked 24 hours ago, it looks like a diminishing chance.
On Sunday, the mountains and east will again see the prospect for afternoon and evening thunderstorms. However, there will be more cloud cover around which will limit instability a bit. For the lowlands of Western Washington, this means a cooler day with increasing onshore flow off the Pacific. Highs will be in the 70s to low 80s.
The storm chances largely go away by Monday, and while we could still have a little bit of haze around, the air will be freshened up by the greater onshore flow. Highs for Seattle will be around 80.
Expect uneventful weather from Monday through at least Wednesday with temperatures near or just a little warmer than seasonal averages – about 80 in Seattle.
Forecast models suggest rain chances could be in the offing by late next week but that’s not a firm consensus. Given we will be approaching the record-longest dry stretch for Seattle by next weekend, we’ll be watching in case some much-needed rain might arrive.
©2021 Cox Media Group