By Reginald Stanley. Posted July 29, 2020, 3:00 PM.

Strong high pressure building over the Desert Southwest will be responsible for a moderate heat wave this week, pushing temperatures well into triple-digits inland from Thursday through Saturday.

The heat wave has prompted the National Weather Service to issue a Heat Advisory for inland Southern California, including the mountains below 5,000 feet. The deserts will be even hotter under an Excessive Heat Warning effective during the same period. Cool sea surface temperatures are expected to moderate temperatures along the immediate coasts, keeping the effects of the heat wave there minimal. The heat wave follows a period of rather mild temperatures across the region since mid-July, as well as a short heat wave earlier in the month. Monsoonal moisture, often a summer staple in Southern California's inland regions, has been absent so far in 2020, mimicking a similar trend during the relatively quiet summer of 2019.

The high pressure ridge is forecast to weaken beginning on Sunday. Onshore flow will usher the return of a deep marine layer later next week.