(KRON) — Part of the North Bay Mountains and East Bay Hills will be under a Red Flag Warning beginning Tuesday night due to dangerous fire conditions, the National Weather Service announced Monday afternoon.

The warning is in effect in areas above 1,000 feet in the East and North Bay.

The National Weather is predicting winds of 20 to 30-mph with gusts up 45-mph.

A Red Flag Warning signifies critical fire weather and a Fire Weather Watch means those conditions are possible, according to the weather agency.

On Sunday, the National Weather Service issued a Fire Weather Watch for the same region.

That has since been upgraded to a Red Flag Warning.

According to CAL FIRE, this week’s “wind event” is short-lived, but will string be strong.

CAL FIRE’S primary message — be prepared.

“The focus is on families and having that evacuation plan ready and monitoring the weather,” said Mike Mohler, CAL FIRE deputy director of communications.

The Red Flag Warning comes as PG&E prepares to shut down power for 264,000 customers in 22 counties, including six in the Bay Area.

The power shutoffs could begin as early as Wednesday morning.

Affected customers should receive notification from PG&E 24 hours before power goes out.

For more on safety and preparedness, click here.

For an interactive map of areas affected by the power outages, click here.