The National Weather Service said Tuesday that there will be enough moisture and lift in the air above the Bay Area late in the night and into early Wednesday for a slight chance of showers and thunderstorms, and some of those storms could result in dry lightning.
The area possibly affected extends from coastal North Bay areas to Big Sur in the south and the Diablo Range to the east.
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.