Yeah, I think those sensors can be a slightly lagging indicator. For what it's worth though, that webcam always looks much worse than reality because it has a ton of zoom on it that magnifies any haze. I usually check the Yosemite falls or ahwahnee meadow cams for a more realistic perspective.
Following this because I was going to spend the weekend up there too. The webcams looked clear all week but I saw that the red flag warnings was extended and the winds may be changing