Red flag warning in effect in Northern California amid high risk of rapid fire spread

An elevated fire danger risk is in effect in California, specifically Northern California, throughout Thursday and Friday.

The National Weather Service issued a red flag warning for California and remains in effect from 11 a.m. on Thursday to 8 p.m., local time Friday.

Critical fire weather conditions will occur Thursday and Friday because of gusty winds and dry conditions, according to the Sacramento NWS.

A weather system passing the Northeast is expected to bring gusty north and east winds to northern California. The strongest winds will be over the west side of the Sacramento Valley and the Coastal Range Foothills, according to the NWS.

"Gusty winds combined with drying fuels will lead to critical fire weather conditions. Lighter winds are expected on Saturday, but humidity values will remain in the single digits and teens," according to the NWS.

Winds are expected from 15 to 30 mph with gusts of 35 to 45 mph, locally up to 55 mph, with very dry conditions and hot temperatures, according to the NWS.

The greatest threat is to the west side of the Sacramento Valley, mainly along and west of Interstate 5 and 505 and into the Coastal Range Foothills below 2500 feet, which will get its strongest winds Thursday night into Friday morning.

Strong winds combined with low relative humidity and warm temperatures can contribute to extreme fire behavior. Gusty winds and critical fire weather make it easier for fires to start and spread quickly, according to the NWS.

NWS Sacramento warned people to avoid outdoor burning, not to use a lawn mower or drive on dry grass or brush, not to have vehicle parts or chains dragging on the ground and to properly dispose of cigarettes and matches.

ABC News' Max Golembo contributed to this report.