The Timber Fire doubled in size for the second day in a row, growing to 2,000 acres, though fire officials say that it is still spreading at a "slow rate of speed" and is not burning across treetops.

The Timber Fire broke out Saturday night around 9 pm in the Los Padres National Forest, southeast of Loma Vista, near Big Sur. What was a 400 acre fire by Sunday evening became 800 acres by Monday morning, and 1,700 acres by Monday afternoon.

The latest Cal Fire update, as of 10:44 am Tuesday, has the fire at 2,000 acres, and evacuation orders have now been issued for four zones along the Big Sur coast, from Pfeiffer Big Sur State Park to the north to Partington Creek in the south. Evacuation warnings have been issued for several other zones as well.

The fire is not a Cal Fire incident, and is being fought by National Forest Service firefighters.

The fire has been burning in steep, remote, rugged terrain in the mountains east of Highway 1, and the firefighting effort has been focused on keeping the fire from jumping the highway.

"Firefighters continued to protect structures primarily near Highway 1 in the Ventana area," officials said in a Tuesday morning update. "They cleared brush and other potential threats around property, set up water systems, and secured access for firefighters and firefighting apparatus."

The offiicials added, "The heavy marine layer prevented night flying helicopters by limiting visibility to dip sites located below the marine layer. Crews are actively working to establish a water dip site above the inversion layer today."

The Timber Fire is just 5% contained, and fire officials say they expect warmer and dryer conditions by midweek over the eastern portion of the fire, which has burned over the other side of the first ridge line.

An air quality advisory has been issued for the South Bay and East Bay as smoke from the fire drifts north out of Monterey County.

Meanwhile, two very large, and swiftly growing fires have merged along the California-Nevada border north of Reno, the Fred Mountain and Bug fires, which now combined cover 44,000 acres. That fire complex is now 4% contained.

Photo via National Forest Service/Cal Fire