Yesterday’s calmer than expected winds, while helpful, weren’t enough to give firefighters the leverage they needed to contain the spreading Sonoma County blaze. Now, 50,000 Healdsburg and Windsor residents are placed under mandatory evacuations.

Burning through more than 25,400 acres (with still only 10 percent containment), Cal Fire has released new evacuation orders for areas of Sonoma and Lake Counties, as well as now parts Healdsburg, according to the Chronicle.

These mandatory evacuations affect some 50,000 residents in Healdsburg, Windsor, and communities along Highway 101 corridor, in addition, the following Sonoma and Lake County areas, via KPIX:

Sonoma County:
Ida Clayton Road. North to Highland Ranch Rd. at Campbell Rd; east of Hwy 101, specific residents between Asti and Alexander Valley Roads; areas and roads leading to Mendocino and Lake County line, which include Lakeview Road and areas south along the Lake/Sonoma County Line, via Ida Clayton Road.
Lake County:
Gifford Springs; Whispering Pines; Anderson Springs; Adams Springs; Hobergs; Cobb

According to the most recent reports, 23,500 structures are currently threatened by the Kincade Fire, which has already destroyed 49 structures, including 21 homes, a number of small businesses, and a handful local wine vineyards.

More than 2,000 firefighters, totaling 53 fire crews, are still battling the blaze as of Saturday afternoon, aided by helicopters and airplanes dropping water and fire retardants from above. The worry now is that with high winds in the forecast today through Monday, there's even less of a chance to make significant headway to contain the inferno.

PG&E is expected to temporarily shut-off power to some 940,000 customers – an increase from the 850,000 estimated on Friday – as reported by SFGate, in an attempt to thwart further wildfire growth. Roughly 48,000 Contra Costa Country account holders are expected to go dark later tonight.

Phased outages are planned for several other Bay Area counties today, tomorrow, and potentially into Monday afternoon, as well. Here’s a more detailed breakdown of today and tomorrow’s scheduled power cut-offs, as reported by SFGate:

PHASE ONE: 2 p.m. on Saturday. Counties impacted: Amador, Butte, Colusa, El Dorado, Glenn, Nevada, Placer, Plumas, San Joaquin, Sierra, Siskiyou, Shasta, Tehama and Yuba.
PHASE TWO: 4 p.m. on Saturday. Counties impacted: Lake, Marin, Mendocino (south), Napa, Solano, Sonoma and Yolo.
PHASE THREE: 5 p.m. on Saturday. Counties impacted: Alameda, Contra Costa, Monterey, San Benito, San Mateo, Santa Clara, Santa Cruz and Stanislaus.
PHASE FOUR: 5 p.m. on Saturday. Counties impacted: Alpine, Calaveras, Mariposa and Tuolumne.
PHASE FIVE: 5 p.m. on Saturday. Counties impacted: Humboldt, Mendocino (north) and Trinity.
PHASE SIX: 10 a.m. on Sunday. County impacted: Kern County.

It remains uncertain as to how the Kincade Fire began, though a broken PG&E transmission line from one of the company's high-voltage towers was found near the fire’s epicenter.

Related: Kincade Fire Reaches 5 Percent Containment, Burns 21,900 Acres
PG&E Tower 'Malfunctioned' Right Near Where Kincade Fire Started

Image: Instagram via @sharayray