Crews concentrated on the fire's northeast corner, where winds could push the fire, said Robin DeMario, fire information officer.
A forecast weekend storm was expected to bring winds of 30-40 mph.
``If we can make it through the next 24 hours ... then they'll start feeling pretty confident that the fire will remain within the fire lines,'' DeMario said Saturday night.
The fire remained 45 percent contained Saturday.
When the fire began Aug. 8, it was 20 miles from Wenatchee. It has since moved down the Wenatchee Valley and its leading edge is about six miles from town, but there is no threat to Wenatchee, she said.
``It would still have to go through a number of canyons'' and fire lines on the eastern edge are secure, she said.
Hundreds of homes in four canyons remained under mandatory-evacuation order Saturday, and residents of hundreds more homes in five other canyons were advised to be ready to leave at a moment's notice.
About 1,810 firefighters were assigned to the blaze, which has destroyed one home and damaged another house and a shed.
The fire, burning on private, state and federal land, was believed to have been human-caused. Investigators ruled out arson but the state Department of Natural Resources continued to investigate.
Elsewhere in central Washington, firefighters continued to battle several wildfires started by lightning.
About 20 miles southeast of Tonasket, a complex of four fires had burned 437 acres by Saturday. Four homes were evacuated because of the Highland complex but the fires were considered 90 percent contained.
About 540 people were assigned to the 900-acre Williams Butte fire, just inside the Sawtooth Wilderness 17 miles northwest of Twisp. It was 45 percent contained.
Another 450 firefighters were assigned to the Pot Peak-Sisi Ridge complex of three fires, which have blackened a total of 47,470 acres near Lake Chelan and were 85 percent contained. The cost of fighting those fires grew to more than $23 million.
The Dirty Face fire near Lake Wenatchee was estimated at 295 acres of heavy brush and timber in very steep terrain. The fire was 90 percent contained Friday night.