Warmer Weather Headed to Culver City

Because of high pressure building over the region, "high temperatures exceeding 100 degrees are likely over much of the coastal valleys and at lower mountain elevations," the National Weather Service said in an advisory.

"The combination of the hot temperatures and humid air mass could allow for heat index values to approach critical levels," it added, warning it will feel even hotter than it is. "Heat index values will soar to near 105 degrees in some valley location ... and to near 100 in some foothill locations."

On Friday, temperatures will start to cool, thanks to monsoonal moisture, which will promote cloud cover, forecasters said. But that same monsoon flow will raise the possibility of thunderstorms in the San Gabriel Mountains and the Antelope Valley, with an outside chance of showers and thunderstorms in other valley areas and near the coast, they said.

"Thunderstorms could produce brief and locally heavy rainfall, gusty winds and dangerous cloud-to-ground lightning," according to the NWS advisory. "... When thunder roars, go indoors. Heat, flooding and lightning are among nature's deadliest killers."

In the meantime, the NWS forecast highs today of 79 in Avalon; 80 at LAX and in Newport Beach; 87 on Mount Wilson; 92 in Long Beach and downtown L.A.; 93 in Anaheim; 94 in San Gabriel; 98 in Pasadena; 100 in Burbank and Palmdale; 102 in Lancaster; 103 in Woodland Hills; and 104 in Saugus.

- City News Service also contributed to this report.