Red Flag Warning Expanded as Wildfire Risk Rises Across Northern California

California fire officials are urging residents to stay prepared for the possibility of fast-moving wildfires as critical fire weather conditions are expected to persist through Thursday.

In an update posted on social media on June 10, CAL FIRE said that the Red Flag Warning had been expanded to include portions of the Bay Area.

The Red Flag Warning was already in effect for some areas of the northern Sacramento Valley from Wednesday morning through Thursday afternoon.

A combination of strong north winds, low humidity, and dry vegetation is expected to result in conditions that can enable a new fire to spread rapidly, the agency warned on social media.

North winds with speeds ranging from 15 to 25 mph are expected, with gusts up to 30 to 40 mph, according to the National Weather Service (NWS).

Daytime relative humidity is expected to range from 9% to 15%, while overnight relative humidity will range between 25% and 50%.

The warning comes as California enters the peak summer wildfire season; strong winds and dry brush can elevate fire danger.

Stating that critical fire weather has been predicted, CAL FIRE later expanded the alert area as weather conditions evolved.

Authorities are urging residents to take precautions before an emergency occurs.

“Be ready, not reactive,” CAL FIRE said in its social media post.

Officials recommend packing a go bag with essential items, ensuring emergency alerts are enabled on mobile devices, and reviewing evacuation plans with family members in case the situation arises.

Residents are encouraged to monitor updates from the National Weather Service and local emergency officials as conditions change.

What is a Red Flag Warning?

The NWS issues a Red Flag Warning when warm temperatures, very low humidity levels, and strong winds are expected to combine to create heightened fire risks in an area.

During a Red Flag Warning period, a small spark can develop into a dangerous fire.

Officials recommend the following precautions during a Red Flag Warning:

• If burning is permitted in any area, all burn barrels must be covered with a weighted metal cover, with holes smaller than three-quarters of an inch.
• Do not throw cigarettes or matches out of a moving vehicle. It may lead to dry grass being ignited and developing into a wildfire.
• All outdoor fires must be extinguished properly. Fires must be extinguished using plenty of water. Residents must stir to ensure everything is cold to the touch.
• Charcoal should be drowned in water until it becomes cold. Live charcoal must not be left on the ground.
• Do not leave a fire unattended. Embers or sparks can blow into leaves or brush, igniting a fire.