The Pickett Fire near Calistoga nearly doubled in size Thursday night, reaching 2,131 acres with no containment, according to Cal Fire.

The Pickett Fire erupted in Napa Valley on Aug. 21 forcing evacuations for many in the area and threatening people, structures and wineries.

The Pickett Fire, burning since Thursday afternoon near Calistoga, is the largest fire this year within the six counties covered by Cal Fire’s Sonoma-Lake-Napa unit. The fire has burned 3,235 acres as of Friday afternoon and was 5% contained, according to fire officials.

The Pickett Fire was reported shortly before 3:30 p.m. Thursday. The California Highway Patrol initially reported smoke was visible from Highway 128.

Firefighters will battle intense heat and dry weather Friday as they work to control a fast-moving blaze in the heart of California’s wine country.