Possible ‘wind event’ could lead to PG&E power shut-offs in Sonoma, 17 other counties

Pacific Gas & Electric Company is warning of a possible “dry offshore wind event” forecast for Tuesday that could possibly lead to power shut-offs affecting as many as 48,000 customers across 18 counties, including hundreds in Sonoma, Napa, Mendocino and Lake counties in the North Bay region.

Meteorologists for PG&E were monitoring the weather conditions, which are expected to continue into Wednesday, according to a news alert issued by the San Francisco-based utility.

“Given this wind event and current conditions including extreme to exceptional drought and extremely dry vegetation, PG&E has begun sending 48-hour advance notifications to customers in targeted areas where PG&E may need to proactively turn power off for safety to reduce the risk of wildfire from energized power lines,” officials said in a Sunday alert. The alert initially included 16 counties but was expanded Monday to include 18 counties.

The month-old Dixie fire, which continues to rage across portions of Butte, Plumas, Tehama, and Lassen counties — and which are all included in the PG&E warning — remains the largest wildfire in the country.

It has scorched more than 900 square miles and, as of Monday, was 31% contained. It started in the northern Sierra Nevada and southern Cascades on July 13 and eventually merged with a smaller blaze called the Fly fire.

It has destroyed more than 1,100 buildings, including 625 homes, and more than 14,000 structures remained threatened.

Investigations are continuing, but PG&E has notified utility regulators that the Dixie and Fly fires may have been caused by trees falling into its power lines.

Thunderstorms that moved in late last week didn't produce much rain but whipped up winds and generated lightning strikes across the northern Sierra where crews were battling the blaze. Extreme heat returned Sunday with temperatures that topped off at 100 degrees.

By Monday morning, conditions that had suppressed the Dixie fire overnight were expected to give way later in the day to winds that could push flames toward mountain communities in a region where drought and summer heat have turned vegetation to tinder.

PG&E said the majority of customers — about 27,000 — that could be affected should power shut-offs become necessary are in Butte and Shasta counties.

Nevertheless, its in-house meteorologists, as well as its Wildfire Safety Operations Center and Emergency Operations Center, continue to closely monitor conditions.

“We will share additional customer notifications as conditions evolve,” the utility said.

Customers can look up their address online to find out if their location is being monitored for the potential safety shutoff at www.pge.com/pspsupdates.

The potential shutoff is expected to affect approximately 48,000 customers across the following counties:

• Butte County: 11,1114 customers, 1,027 Medical Baseline customers
• Colusa County: 509 customers, 33 Medical Baseline customers
• Glenn County: 207 customers, 10 Medical Baseline customers
• Humboldt County: 681 customers, 16 Medical Baseline customers
• Lake County: 2,083 customers, 136 Medical Baseline customers
• Lassen County: 65 customers, 7 Medical Baseline customers
• Mendocino County: 669 customers, 30 Medical Baseline customers
• Napa County: 2,041 customers, 99 Medical Baseline customers
• Nevada County: 133 customers, 3 Medical Baseline customers
• Plumas County: 660 customers, 24 Medical Baseline customers
• Shasta County: 19,999 customers, 1,713 Medical Baseline customers
• Sierra County: 1,036 customers, 30 Medical Baseline customers
• Solano County: 44 customers, 3 Medical Baseline customers
• Sonoma County: 240 customers, 9 Medical Baseline customer
• Tehama County: 7,473 customers, 671 Medical Baseline customers
• Trinity County: 428 customers, 21 Medical Baseline customers
• Yolo County: 11 customers, 0 Medical Baseline customers
• Yuba County: 487 customers, 47 Medical Baseline customers.

The Associated Press contributed to this report.