NAPA (CBS SF) -- Winds howled across the mountains and hills of the North and East Bay early Monday with gusts topping 60 mph on the highest peaks as Red Flag Warning conditions gripped the region and Pacific Gas & Electric prepared to turn off power to customers in Napa and Solano counties as a wildfire precaution.
The National Weather Service said the warning would be in place until 8 p.m. for the North and East Bay hills as well as the East Bay interior valleys.
"Mount St Helena had gusts around 57 mph by 11:20 p.m. and they have increased overnight," NWS forecasters said. "Since midnight, that site has seen sustained winds ranging 50-54 mph with gusts 57 to 66 mph."
Meanwhile in the East Bay, forecasters said the Mount Diablo's weather station had seen sustained winds of 34-43 mph with gusts ranging 43-52 mph over the same time span.
Elsewhere, 40 mph wind gusts were clocked in Healdsburg, 22 mph in Berkeley and 18 mph in Orinda.
Temperatures will also be on the rise and humidity levels will dip to as low as 14 percent. Gusty winds, high temperatures and low humidity levels are a formula for prime wildfire conditions as the parsed hillsides become even more tinder-dry.
Orinda resident Sandy Barnett said once she got a notice from her city officials of the Red Flag Warning, she made sure her bags were packed.
"When I got the notice of the Red Flag Warning, I immediately went to where I have my bags packed," she told KPIX 5. "I checked to make sure I had everything in there and that I'm ready in case anything happens, I want to be ready to rock and roll."
Barnett says if she needs to evacuate, she only has two roads, and they're generally narrow.
"I have all my medications, just today I charged up my things that I can charge my cell phones," she added.
Roger Wood said if you live in the East Bay hills, you always have to be vigilant during these kinds of weather conditions.
"It's always the possibility that it could strike here," he said. "This place (Orinda) is very vulnerable and when you reflect on other communities that get hit by fire, it's frightening."
In addition to the East Bay hills and valleys, the North Bay mountains were also included in the red flag warning.
"This weather system that we're seeing coming in tomorrow morning is very dynamic. It has been a little wet, a little sprinkle, a little moisture in the air," said Deanna Contreras, spokesperson for PG&E.
The warm temperatures will linger after the warming expires.
"Highs on Tuesday should be the hottest temperatures this week with widespread 90s into the low 100s for inland areas and even the coast should see mid 70s into the upper 80s," the weather service said.
Meanwhile, Pacific Gas & Electric said it was poised to shut off power at dawn to customers in both Napa and Sonoma counties. As of Sunday evening, utility officials said, they expected the shut off to impact 1,225 customers in Napa County and 802 customers in Solano County.
But by Monday morning, the number had dwindled to less than 200 customers who actually had lost power.
Customers can look up their address online to find out if their location will be affected at www.pge.com/pspsupdates.
Monday's PSPS was the second for the Bay Area this year.
Betty Yu contributed to this report.
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