Brutal heat baked the Southland again Sunday and at least 30,000 homes and businesses went without power as the heat melted electrical equipment amid heavy demand. Temperatures were lower than Saturday’s record-breaking highs, but the National Weather Service issued an “excessive heat warning” for the second consecutive day. The heat warning expired at about 7 p.m. The National Weather Service also issued a flash flood warning as thunderstorms battered the San Gabriel Mountains and adjacent foothills of the Antelope Valley. The warning was issued shortly before 2p.m. and expired a little more than a hour later. “A flash flood warning means that flooding is imminent or occurring,” the NWS announced. “If you are in the warning area, move to higher ground immediately.” In Woodland Hills, which had the dubious distinction of being the hottest spot in Los Angeles County on Saturday with a record-breaking 119 degrees, by 3 p.m. Sunday, the temperature was a relatively balmy 91 degrees. Gale Harris from the Department of Water and Power said 20,000 customers in the San Fernando Valley and 10,000 people in metropolitan Los Angeles were without power Sunday, due to over-heated equipment going out.160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! AD Quality Auto 360p 720p 1080p Top articles1/5READ MORE11 theater productions to see in Southern California this week, Dec. 27-Jan. 2NWS forecasters were noting a slight drift of the sweltering system toward the east. They expect a gradual decline in temperatures by a few degrees each day through the middle of this week. “It will be gradual thing, a very gradual thing,” Bill Hoffer, an NWS meteorologist, said. Whittier hit a high of 90 Sunday. Some scattered power outages were reported in parts of unincorporated Whittier, police reported, and some lightning strikes occurred in La Mirada. No damages or injuries were reported, police said.