(CNN)Hundreds of California residents are under evacuation orders after new fires were sparked Wednesday, with another heat wave expected to make fighting the flames even more challenging.
Northern California wildfires traveled up to 8 miles in a single day, Cal Fire says
California is already battling the massive Dixie Fire, the state's second-largest fire and 14th most destructive on record, which has now grown to more than 747,000 acres and remains 45% contained. The blaze is threatening more than 11,800 structures and has prompted evacuation orders and warnings in Plumas, Lassen, Butte, Tehama and Shasta counties.
"Fires burning in Northern California are exhibiting extreme fire growth based on critical fuel conditions," Cal Fire said in an incident update on Thursday. "Under these drought conditions, wildfires are burning rapidly with extreme severity and have traveled up to 8 miles in a single day. Fuel conditions are much worse than previous years and along with wind is causing much greater fire spread. Firefighters are experiencing conditions never seen before, such as increased spread rates, spotting and active nighttime burning."
Another wildfire burning in Northern California's Trinity National Forest is the Monument Fire, which has burned 157,287 acres and is 20% contained.
Meanwhile, the Caldor Fire has scorched 136,643 acres since it began August 14 and was 12% contained Thursday morning, according to Cal Fire. The fire, burning in El Dorado and Amador Counties, is the state's number one priority, officials say.
"We get the first opportunity for additional resources that become available," Cal Fire Incident Commander Dusty Martin said in a briefing Wednesday night. "We have been very fortunate in the past couple of days where we've seen a huge influx of resources into the Caldor Fire and as our operations talked about, we're starting to see the fruits of those labors."
"We're starting to gain ground on this fire and it's making a difference," he added.
The city of South Lake Tahoe declared an emergency Thursday as accelerating winds pushed the Caldor Fire closer to the popular tourist destination.
"With red flag conditions possible over the coming days, the Caldor Fire could spread rapidly into more populated communities and significantly broader areas," the Governor's Office of Emergency Services said in a statement, adding that communities up to and including South Lake Tahoe may have to evacuate.
While the city's emergency proclamation does not include evacuation orders, it does leverage state and federal resources to direct immediate disaster relief funds and waive certain rules for greater flexibility, the city government said in a news release posted on Facebook.
"At this time, we are prepared should an evacuation become necessary, but the firefighters on the front lines are doing incredible work to secure the perimeter of the fire and our hope is that they are able to prevent the fire from encroaching any further into the Tahoe Basin," city spokesperson Lindsey Baker told CNN.
The city's emergency declaration comes after evacuation orders were issued to Echo Summit and warnings were extended for the first time to portions of the Tahoe Basin, including Christmas Valley, which is just south of the city of South Lake Tahoe.
The last time South Lake Tahoe was under mandatory evacuation orders was in 2007, when parts of the region were ordered to leave due to the Angora Fire, Baker said. The city is home to more than 22,000 people.
Firefighters battled 34 new blazes in the state Wednesday, Cal Fire said, attributing two new large fires to drought conditions.
As of Thursday morning, 33,323 people in California were under evacuation orders due to the wildfires, according to the Office of Emergency Services.
The Airola Fire was sparked in Calaveras County and prompted officials to issue evacuation warnings and orders, according to the county's sheriff's office. The fire has scorched about 700 acres and is 10% contained.
In San Bernardino County, the South Fire scorched 700 acres and destroyed 18 structures, including numerous homes, after it started Wednesday and was 0% contained, Cal Fire said on Thursday. The fire is burning near Lytle Creek, a small community in the San Gabriel Mountains.
"We've lived here over 30 years and this is the fastest I've ever seen a fire progress," a resident told CNN affiliate KABC. "We got home and there was no time to evacuate, no time to get anything so it's just whatever we're wearing, this is it."
"We know several of our neighbors' homes (have) burned, we're still not sure what the status is of our house," the resident added.
Parts of the county were put under evacuation orders and warnings while other residents were advised to shelter in place, the San Bernardino County Sheriff's Department said Wednesday in a Facebook post. The evacuation orders are in effect for 1,000 people, officials said.
Laura Mills told CNN affiliate KCBS she lives in in the area where the fire is currently burning.
"I came home and got the dogs," she told the news outlet. "Hopefully our house is going to make it."
Meanwhile, the Bennett Fire began Wednesday in Nevada County and prompted officials to issue evacuations in some areas as well as order others to shelter in place, the county's office of emergency services said in a tweet. As the 59-acre fire was 70% contained, Cal Fire said, and some of those evacuation orders were lifted.
So far this year, firefighters have battled 6,773 new wildfires across the state that have burned more than 1.6 million acres, according to Cal Fire.
In the same time period last year, crews battled 7,389 fires.
According to Cal Fire, Northern California has so far experienced large fire activity and will "likely experience an extended fire season."
The Office of Emergency Services says nearly 700 people are seeking shelter in 16 facilities throughout the state.
"Don't wait, evacuate!" is their reminder to residents to heed emergency notifications.
Temperatures are expected to be 5 to 10 degrees above normal through the weekend in California, CNN meteorologist Michael Guy said.
And while this isn't uncommon for the region during this time of year, "any type of temperature increase is not good for the firefighters or any personnel fighting the fires with their exposure to intense temperatures as it is," Guy said. He noted that the warmer weather is not expected to worsen the current fire conditions.