SACRAMENTO, Calif. — After one of the most intense heat waves ever recorded for Northern California in September, the region will see rapid weather changes.
Strong winds are moving in Tuesday with strong gusts in the valley up to 30 mph and 50 mph for the Sierra. The air will also be warm and very dry with relative humidity in the single digits at times.
Fires will grow very quickly in these conditions and a Red Flag Warning has been issued for almost all of Northern California except for the immediate coastal areas.
Winds will be strong in general in the valley with blowing dust and sustained wind in the 25 mph range. Light objects should be secured.
Power safety shutoffs began early Tuesday with more than 170,000 customers in the dark as PG&E shut off main powerlines in very windy areas. Communities with lighter winds are still affected since their power source upstream has been interrupted.
Temperatures will come down from Monday's record highs. Highs are expected in the mid-90s to about 100 degrees.
The wind should start to die down Wednesday morning for coastal areas and by noon in the valley and Sierra with the Red Flag Warnings expiring.
The most critical time might be overnight Tuesday in the Sierra with many people without power, and asleep when a fire and evacuations may occur.
WATCH MORE: PG&E Power Shutoffs: Power out for 172,000 customers because of fire risk | Tuesday morning update
PG&E is turning off power to about 172,000 customers in California on Tuesday because of fire risk. PG&E calls these Public Safety Power Shutoffs.