"Red flag Warnings span from Kansas to Minnesota and reiterate the potential for fires to spread rapidly," the NWS said.

The National Weather Service has issued a Red Flag Warning for the Mother Lode and the northern San Joaquin Valley, through 5 PM Saturday Minimum daytime relative humidity of 5 to 20 percent is expected. Moderate to poor overnight relative humidity recoveries will range from 25 to 50 percent.