The in the Bay Area has prompted the National Weather Service to issue a red flag warning for the East Bay hills Wednesday night and early Thursday.
The relatively rare chance of thunderstorms in early September is due to the remnants of a tropical storm passing through the area.
Here's the definition of a red flag warning from the National Weather Service: "A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL."
