The California Independent System Operator (ISO) has issued a statewide Flex Alert for 4 p.m. to 9 p.m. Wednesday because predicted scorching temperatures may drive up energy demand and tighten available power supplies.

Temperatures, forecast to be over 100 degrees in inland areas of Northern California, will likely drive up air conditioner use. The power grid operator is calling for voluntary conservation to help balance supply and demand.

The state urges people to conserve electricity, especially during the late afternoon and early evening, when the grid is most stressed due to higher demand and less solar energy. Reducing energy use during a Flex Alert helps stabilize the power grid during a time of tight supply, preventing further emergency measures that include power outages.

The ISO recommends that, before 4 p.m., energy users pre-cool their homes by setting the thermostat to as low as 72 degrees and use major appliances, if necessary. Adjust blinds and drapes to cover windows.

During the Flex Alert from 4 p.m. to 9 p.m., Californians should set thermostats to 78 degrees or higher if health permits, avoid using major appliances, and turn off all unnecessary lights.

Find out more about flex alerts at https://bit.ly/3PvxP91. Follow grid conditions at https://bit.ly/3QtdfHG.

In other news

* The National Weather Service said there will be enough moisture and lift in the air above the Bay Area late in the night Tuesday and into early Wednesday for a slight chance of showers and thunderstorms.

The area possibly affected extends from coastal North Bay areas to Big Sur in the south and the Diablo Range to the east.

Some of the storms could result in dry lightning, the weather service reported, saying this is a "low confidence high impact" situation.

Fire danger is already high in the Bay Area and Northern California, as inland temperatures will reach triple digits Tuesday through at least Thursday, prompting an excessive heat watch. People are advised to drink plenty of water, check on elderly people and those without air conditioning, and to limit outdoor activity when possible.

For Bay Area weather updates, go to https://www.weather.gov/mtr/.

* The Bay Area Air Quality Management District has issued an air quality advisory for the region for Wednesday because of smoke from a wildfire elsewhere in the state.

The air district had issued a Spare the Air alert for the Bay Area for Tuesday due to triple-digit weather in parts of the region as well as smoke from the Six Rivers Lightning Complex Fire burning in Humboldt and Trinity counties.

Hazy skies and the smell of smoke may been seen and smelled in certain parts of the region Wednesday, but pollution levels are not expected to exceed the 24-hour national standard that would prompt another Spare the Air alert. Air quality readings are available at baaqmd.gov/highs.