A weather system brushing the state this weekend will cause a welcome improvement in air quality and visibility. However, despite the breezes and air mass exchange, the long term smoke/haze situation will not be fully resolved until the western North American wildfires are extinguished and the smoke source is eliminated.
Saturday’s cooler and fresher air mass may not decrease high temperatures to the full potential since the clearing skies will mean increased solar radiation relative to recent smoky days, according to Washington State University’s AgWeatherNet.com’s Weekly Weather Outlook.
As the disturbance clips the northern part of Washington, some clouds and western showers are likely for the start of the weekend. Sunday morning should be rather pleasant, with relatively cool temperatures compared to recent months. However, another ridge of high pressure is expected to build across the Northwest early next week, as warm, dry, and calm conditions return to the region.
As always, the fire/smoke situation will be difficult to predict. Working from the premise that the smoke and haze has been worse than anticipated, I expect a notable deterioration of air quality at that time. Luckily, a breezy weather system could bring another interval of at least temporary smoke and heat relief later in the period. Although temperatures should generally be near to above normal in the coming days, at least we seem to be entering a more variable regime. As a result, there look to be periodic respites from the heat and smoke. Unfortunately, the smoke this summer has exhibited similar behavior.. Just when you think you are rid of it, it returns once again. In any case, Washington’s mid-September weather may not be ideal, but it should be better than it has been.
For the complete AgWeatherNet Weekly Weather Outlook for Sept. 9 to Sept. 15, 2017, please click the following link: