DISASTERS

Blanket of heat covers California while lightning, hard rain hit mountains and deserts

  • Thunderhead cloud formations are seen over downtown Los Angeles Wednesday, Sept.  9, 2015. Southern California will see dangerously high temperatures this week and a chance of thunderstorms and flooding in the mountains as a building high-pressure system delivers a late-summer scorching, forecasters said Tuesday. (AP Photo/Nick Ut)

    Thunderhead cloud formations are seen over downtown Los Angeles Wednesday, Sept. 9, 2015. Southern California will see dangerously high temperatures this week and a chance of thunderstorms and flooding in the mountains as a building high-pressure system delivers a late-summer scorching, forecasters said Tuesday. (AP Photo/Nick Ut)  (The Associated Press)

  • Thunderhead cloud formations are seen over the Metro Rail on the Metro Gold line downtown Los Angeles Wednesday, Sept.  9, 2015. Southern California will see dangerously high temperatures this week and a chance of thunderstorms and flooding in the mountains as a building high-pressure system delivers a late-summer scorching, forecasters said Tuesday. (AP Photo/Nick Ut)

    Thunderhead cloud formations are seen over the Metro Rail on the Metro Gold line downtown Los Angeles Wednesday, Sept. 9, 2015. Southern California will see dangerously high temperatures this week and a chance of thunderstorms and flooding in the mountains as a building high-pressure system delivers a late-summer scorching, forecasters said Tuesday. (AP Photo/Nick Ut)  (The Associated Press)

  • Travelers stand in line behind a big electric fan at Los Angeles Union Station in Los Angeles, Wednesday, Sept. 9, 2015. Temperatures reached 99 degrees before noon in downtown Los Angeles. Hundreds of cooling centers are open in senior centers and libraries around the state as excessive heat warnings were issued into tomorrow night in many areas, especially the valleys and lower mountain elevations. (AP Photo/Nick Ut)

    Travelers stand in line behind a big electric fan at Los Angeles Union Station in Los Angeles, Wednesday, Sept. 9, 2015. Temperatures reached 99 degrees before noon in downtown Los Angeles. Hundreds of cooling centers are open in senior centers and libraries around the state as excessive heat warnings were issued into tomorrow night in many areas, especially the valleys and lower mountain elevations. (AP Photo/Nick Ut)  (The Associated Press)

California is in for more blistering heat before gradual cooling sets in over the weekend.

The National Weather Service predicts dangerously high temperatures again in portions of southwestern California but says Thursday should be the peak of the heat event.

Heat advisories are also in effect for the inland portions of the San Francisco and Monterey Bay regions.

Southern mountains and deserts remain under a flash flood watch due to a monsoonal flow of moisture from Hurricane Linda in the Pacific off Mexico.

Downpours from afternoon thunderstorms have repeatedly hit southern counties this week, including more than an inch of rain that fell in the Oak Glen watershed of the San Bernardino Mountains on Wednesday.

Portions of the southern coast will also see high surf generated by Hurricane Linda.