INLAND EMPIRE METRO: Excessive Heat Warning through Saturday. High clouds clearing on Friday. Highs through Saturday 100-105. Daybreak lows around 72.

MOUNTAINS: A slight 23% chance of an afternoon or evening shower or thunderstorm. Excessive Heat Warning through Saturday. Resort-level highs through Saturday from the 90s to 106.

DESERTS: A slight chance of an afternoon or evening shower or thunderstorm in the northern deserts. Otherwise partly cloudy and continued hot with an Excessive Heat Warning. Highs through Saturday from 107 to 119.

BEACHES: A few overnight clouds with patchy morning fog. Otherwise, mostly sunny with highs through Saturday to 78. Surf 2-4 feet. Water 60-68.

SUMMARY: With just days before the official start of summer, Southern California is wilting under a heat wave that won’t ease until the weekend.

Long duration heat wave through June 20
 High Temperatures 10 to 20 degrees ABOVE average
 Near record levels inland
 Warmer nights
 Fire weather extremes due to heat and dry air then breezy wind
early next week (during cool down period)
 Dry air but isolated thunderstorms possible mountains and High
Desert
 Fog on the beaches so cooler shallow marine layer into weekend
 Deeper marine layer and cooler to AVERAGE all areas next week

Enough high level moisture has filtered into the Southland to cause isolated thunderstorms in the mountains and northern deserts. They’re the forerunners to the summer monsoon season.

The record-setting heat wave has reached the half-way point. An Excessive Heat Warning won’t be lifted until late Saturday in all areas except the Southern Deserts.

Wednesday’s highs set records in San Jacinto (107), Idyllwild (104) and Big Bear (90)

The summer solstice arrives Sunday. The opening days of summer across the inland valleys will be mostly in the 90s.