California heat wave: Flex Alert extended through Labor Day

Weather Forecast for Sunday, Sept 4

The latest forecast for the greater Los Angeles area, including beaches, valleys and desert regions.

LOS ANGELES - The California Independent System Operator extended a statewide Flex Alert through Labor Day in an effort to conserve energy and prevent blackouts as a scorching heat wave continues through Southern California.

The ISO — which manages the state's power grid — originally issued the Flex Alert back on Thursday as the state began to see temperatures rise into the triple digits. But the heat has not let up. Temperature records were set Sunday across Los Angeles County.

Long Beach's high of 108 degrees broke the previous record of 107 set in 1988, according to the National Weather Service. Lancaster's 109 was one degree higher than the previous record of 108 set in 1955. Palmdale's 106 tied the record set in 1947 and in Sandberg, near the Grapevine, Saturday's 99 degrees broke the previous record of 97 degrees, set in 1955.

"With excessive heat in the forecast across much of the state and Western U.S., the grid operator is expecting high electricity demand, primarily from air conditioning use, and is calling for voluntary conservation steps to help balance supply and demand," Cal-ISO said last week.

During the voluntary Flex Alerts, Californians are asked to:

Set thermostats to 78 degrees or higher
Avoid using major appliances
Turn off unnecessary lights, and
Avoid charging electric vehicles.

Residents are also advised to pre-cool their homes as much as possible and close blinds and drapes to keep interiors cool.

The alerts have worked thus far, with the state avoiding involuntary power cutoffs. Officials said Sunday, Monday and Tuesday in particular are shaping up to be the most difficult days of the heat wave. Tuesday's peak demand is forecast to be 50,087 megawatts, just shy of the all-time record of 50,270 set in 2006.

According to Cal-ISO, electrical demand on Saturday was 45,829 megawatts, and the forecast for Sunday was about 45,000.

The five year-round pools operated by the Los Angeles County Department of Parks and Recreation, which are usually closed on Labor Day, will open on Monday because of the heat, the department's Director Edith García- Gonzalez told City News Service.

Cooling centers for Los Angeles County can be found at ready.lacounty.gov/heat/. Cooling centers for the city of Los Angeles can be found at emergency.lacity.org/la-responds/beat-heat, or by calling 311.