Cal Fire's Pimlott described the effect on the weather as "a tornado over this fire."
"Fire was whipped up into a whirlwind of activity," he said, adding, that it was "uprooting trees, moving vehicles, moving parts of roadways."
Shadrac Herrera of Redding, 34, said he witnessed the upheaval. "I saw a tornado of fire," he said. "I could hear it whistling and sucking up air and at the same time it was growing. Incredibly scary."
Firefighters did not expect much relief from the weather, influenced by a high pressure system over the Southwest that has goosed temperatures from Phoenix to San Francisco.
The National Weather Service forecasted high temperatures for Redding of 110 Friday and Saturday, with overnight lows expected to dip only into the mid-70s.
Early evening gusts could reach speeds of 30 miles per hour, but winds were expected to slow to 10 miles per hour or less by midnight, said federal meteorologist Hannah Chandler. High temperatures were forecast to reach the low 100s Monday and beyond, she said.
Asked if that represented a reprieve from record-setting temperatures along the West Coast, Chandler confirmed, "That is a cool down."