The following link might provide some insight in how fall Chinook might react to warm water temperatures.

Current lake Washington temperatures are 73 degree; highest seen for this date yet the Chinook seem to be entering the locks at normally.

Something to keep in mind on Willapa is that those high temperatures are surface temperatures and every high tide there is a push of deeper cool water that enters the bay allowing the fish to ride into bay on that cool water. Even during those 90 degree days in late August one would see the surface water temperatures drop as much as 15 degrees on the high tide push. While the Chinook may have related to the bottom a little more than normal there seem to be expected numbers of fish given the forecasts and even some coho.