Parts of the Bay Area were bracing late Tuesday ahead of a powerful Pacific storm expected to bring heavy rain and high winds to the region. Evacuation orders were also issued in several communities that were impacted by last summer’s lightning-sparked fires.

In Napa County, an evacuation warning was declared Tuesday evening for residents living in burn areas considered at higher risk of flash flooding, mud, and debris flows.

The warning for the period overnight from Tuesday to Wednesday is based on an updated briefing from the National Weather Service, officials said.

The flash flood watch by the NWS extends from 4 p.m. Tuesday to 4 p.m. Thursday for the LNU Lightning Complex and Glass Fire burn scar areas, with the heaviest rain predicted for Tuesday night to 10 p.m. Wednesday.

“This evacuation warning is to advise residents within fire-impacted areas to remain alert to possible threats and to consider safety plans in the event of a life-threatening emergency. There is no immediate need to evacuate,” officials said.

The NWS advised that “rainfall thresholds may trigger the issuance Flash Flood Warnings overnight and residents in impacted areas may receive (emergency) alerts on Tuesday night into Wednesday morning.”

Residents near the two burn scars should prepare for potential debris flows, landslides, and flooding, officials said, advising, “If you feel the need to leave, now is an opportunity to do so safely.”

There is also a high wind warning issued for midnight to noon on Wednesday.

“Strong and damaging winds could cause downed trees and tree limbs, possibly impeding evacuation routes” and causing power outages, officials said, advising residents to keep cell phones charged and monitor local radio stations for information.

Santa Cruz County

Santa Cruz County also issued evacuation orders Tuesday in anticipation of the storm, county officials said.

Due to the high possibility of debris flow on burn scars, an additional zone in the Ben Lomond Fire Protection District has been ordered to evacuate effective immediately. Other parts of the Ben Lomond district, the Boulder Creek and Felton fire protection districts and Santa Cruz County Fire Department were also already under evacuation orders.

People can use an online tool provided by Zonehaven to see if they are in an evacuation zone.

The county is setting up “temporary evacuation points” at San Lorenzo Valley High School at 7105 state Highway 9, Scotts Valley Community Center at 360 Kings Village Road, and Pacific Elementary School at 50 Ocean St. The locations are not for overnight shelter, according to the county.

Monterey County

The Monterey County Sheriff’s Office on Tuesday afternoon issued evacuation orders for areas within and 2 miles downslope of the burn scar from last year’s Dolan Fire.

The order took effect at 1 p.m. and is in effect until Wednesday morning for weather that could cause mudslides, downed trees and power lines, and other problems.

A map of areas under the evacuation orders in Monterey County can be found online.

State Highway 1 will close Tuesday evening along the Big Sur coastline, according to Caltrans.

The highway closure, which began at 5 p.m. between Ragged Point in San Luis Obispo County and Deetjen’s Big Sur Inn in Monterey County, will remain in effect until Thursday.

Caltrans is working with local law enforcement to limit travel into the Big Sur area and to allow people to evacuate safely. Barricades, cones and signage will be placed at both ends of the closure to warn people.

Santa Clara County

The NWS issued a flash flood warning in parts of Santa Clara County with heavy expected to start around 10 p.m. Tuesday.

The storm, which is expected to last into early Wednesday, may have up to 6 inches in some areas with potential wind gusts of 20-30 mph and localized gusts of up to 60 mph.

San Jose city officials anticipate potential flooding in the downtown and Willow Glen area — the most affected being the Guadalupe River along Willow Street and Ross Creek in the Cherry Area, City Councilmember Dev Davis said in an email.

Davis also mentioned the city has plans in place to open an evacuation center at the Camden Community Center if needed.

Bay City News contributed to this story.