When the trough is positioned to our west, that will pull hot surface air from Eastern Washington, down the western slopes of the Cascades, and out toward the offshore trough. As a double whammy, as air sinks, it also warm, making it feel even hotter.

We'll stay hot until the trough moves overhead and then jumps the Cascades into Eastern Washington. At that point, now we're on the west side of the trough, where air is rushing in from the cool, Pacific ocean and it'll cool us off quite rapidly.

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