The National Weather Service issued warnings for critical fire weather conditions into Saturday, saying a series of dry low-pressure systems passing through the region would bring afternoon wind gusts. The forecast includes extremely low humidity levels that leave vegetation ready to burn.
The blaze in the Redding area, 225 miles (360 kilometers) north of San Francisco, is the largest of 18 wildfires burning throughout California.
Due to the Ranch fire's behavior, fire officials early Wednesday issued new advisory evacuation warnings to residents of the Lake Pillsbury basin, Paradise Valley and in the Mendocino National Forest in Lake County.
As for the River Fire to the south, Blankenheim said firefighters "had really good progress" tying in containment lines in an effort to protect Scotts Valley and keep the fire from jumping Scotts Valley Road.
But tens of thousands of others were still under evacuation orders.
California's current year-round fire season is producing more extreme and destructive blazes than in the past.
The blaze has consumed more than 141,000 acres in Shasta and Trinity counties and as of this morning was only 41 percent contained, according to Cal Fire.
However, some days-old evacuations were lifted Friday in an area near Redding, where armies of firefighters and fleets of aircraft have been battling an huge blaze about 100 miles (160 kilometers) south of the OR line.
"We're looking really good on the southern end of the River Fire", Blankenheim said earlier in his update Friday evening, after parts of Kelseyville and Lakeport were repopulated and Highway 175 was reopened.
Fires are now burning across 1.4 million acres in 13 states, driven by windy conditions and a dry, hot summer. Jerry Brown. "We're being surprised".
The fire burned slowly for days before winds suddenly whipped it up last week and drove it furiously through brush and timber.
The Carr Fire spawned a "fire whirl" of flames and winds in excess of 143 miles per hour (230 kph) on July 26 that had the strength of a severe tornado and uprooted trees and toppled power lines, according to a tweet by the National Weather Service.
The California Department of Forestry and Fire Protection, which uses acres to describe fire size, said the blaze had blackened almost 206 square miles. The fire had reached into remote areas of the country's third-oldest national park.
Friday, flames from the Ranch Fire burned just shy of the southern portion of the Mendocino National Forest but that didn't stop community members from meeting to voice their concerns. "Yosemite Valley is closed at least through Sunday, August 5".