High temperatures for Thursday will be slightly cooler from where they were today, although still running around 5 to 10 degrees above the seasonal average for this time of year for most locations, especially within the inland valleys.
By Saturday, the area of low pressure is going to be moving over the region and allowing for much cooler air to move in with highs 5 to 10 degrees below the seasonal average for this time of year. Further cooling will follow into Sunday.