Heat advisory, red flag warning issued for Thursday

Temperatures are expected to be Thursday, when 15 to 25 degrees above normal, afternoon highs low 90s to low 100s up to 105 in hottest interior locations.

The hot weather and expected increase in air conditioning use comes as the California Independent System Operator has issued a statewide Flex Alert, calling for voluntary electricity conservation from 3 p.m. to 10 p.m. Thursday.

Flex Alerts are given “when the electricity grid is under stress because of generation or transmission outages or from persistent hot temperatures. Consumers are urged to voluntarily conserve electricity to help avoid rotating outages.”

Energy conservation is especially important in the late afternoon and early evening, when demand peaks and solar energy production declines, ISO officials said.

Consumers are asked to turn off unneeded lights, delay using major appliances until 10 p.m., and set air conditioner thermostats to 78 degrees or higher. Conservation steps can lessen the chance of rotating power outages being used to ease the strain on the grid.

Other steps include unplugging unused electrical devices, closing window blinds and drapes, using fans when possible, and limiting time the refrigerator door is open.

In addition to hot weather, the National Weather Service says its simulations indicate “a lot of smoke from the August and North Complex fires will be coming towards the Bay Area and joining with the Glass Fire smoke.”

Spare the Air alerts have already been issued through Friday due to smoke from wildfires.

These advisories come on top of a red flag warning of high fire danger starting at 1 p.m. Thursday from the National Weather Service for North Bay mountains and the areas in and around where the 48,440-acre Glass Fire is burning.