SACRAMENTO (AP) – Managers of California’s power grid asked for voluntary electricity conservation Friday as forecasters predicted more extreme heat statewide.

The California Independent System Operator predicted demand on the system would set a record higher than the 50,270 megawatts on July 24, 2006.

Consumers were asked to cut back on use of electricity between 1 p.m. and 10 p.m. when use of air conditioners is at its peak.

The National Weather Service said a weeklong heat wave generated by high pressure over the West was nearing its peak. People were urged to take precautions against heat-related illnesses – especially the elderly, infirm and children.

Inland areas north and east of San Francisco Bay were expected to bake in triple-digit heat of up to 115 degrees, and even the usually temperate coastline had 80s and 90s in the forecast.

The outlook was the same in Southern California as the region faced a combination of strong high pressure and weak onshore breezes from the Pacific Ocean to land.

“Dangerous heat across SoCal!,” the Los Angeles-area weather office website declared.

Southern California has also had lightning, thunder, downpours and localized street flooding fed by monsoonal moisture.

Forecasters said more could be expected when remnants of Tropical Storm Lidia move north from Mexico’s Baja California during the weekend.

Warnings of excessive heat also blanketed the 450-mile (724-kilometer) length of California’s central valley agricultural heartland and portions of the western slope of the Sierra Nevada.

Copyright 2017 The Associated Press.