California utility PG&E (PCG) may reportedly shut off the power to as many as 500,000 residents in 15 counties in the Sierra Foothills and North Bay this week for two days or more as the threat of wildfires increases.

The company issued the warning saying that the counties of Amador, Butte, Calaveras, El Dorado, Lake, Mendocino, Napa, Nevada, Placer, Plumas, San Mateo, Sierra, Sonoma, Sutter, and Yuba could be affected by the power outage, starting late Wednesday evening.

PG&E issued a 48-hour notice to about 209,000 customers after monitoring a “dry, offshore wind event.” The company said the Public Safety Power Shutoff (PSPS) would occur at different start times for residents, which would be notified via text, email, and automated phone call beginning on Monday. Customers that do not verify that they have received the safety message about the power outages will be visited by a PG&E employee, according to the company.

PG&E said the power outage is necessary to reduce the risk of “catastrophic wildfire ignitions.” The wind conditions slated for this week could potentially increase the risk of damage and hazards from the utility’s power lines, which could cause “rapid fire spread,” it added. Wind gusts in the region could reportedly exceed 55 mph late Wednesday evening into Thursday afternoon.

"The sole purpose of PSPS is to significantly reduce catastrophic wildfire risk to our customers and communities,” Michael Lewis, senior vice president at PG&E Electric Operations, said in a statement.

“We know that sustained winds above 45 mph are known to cause damage to the lower-voltage distribution system and winds above 50 mph are known to cause damage to higher-voltage transmission equipment.

“As we saw in the last PSPS event, we had more than 100 instances of serious damage and hazard on our distribution and transmission lines from wind gusts of this strength," he added.

PG&E said that state officials have classified more than half of its 70,000 square-mile service area as having a “high fire threat.” This is based on the dry grasses, and large amount of dead and dying trees in the region, which the utility said has tripled in size over the last seven years.

The news of more power outage comes less than two weeks after PG&E shut off the electricity to 2 million customers for several days, USA Today reported. PG&E has said the outages are necessary and crucial to the safety of its customers after filing for bankruptcy in January amid liability for the deadly Northern California wildfires.

Shares of PG&E stock were up 0.56 percent as of 2:12 p.m. ET on Tuesday.