Pacific Gas & Electric Co. is warning Northern California customers that power shutoffs will be implemented this week due to heightened fire danger.

The utility said it is monitoring a wind event forecast to hit the region by Wednesday for expected public safety power shutoffs.

Wind gusts are expected to reach around 30 to 45 mph, with peak gusts in North Bay mountains, including Mount St. Helena, forecast to reach around 50 to 60 mph.

With low humidity also expected, officials are concerned about elevated fire danger. The National Weather Service has already said a red flag warning will go into effect at 11 a.m. Wednesday for the northern Sacramento Valley.

PG&E said shutoffs will be required starting Wednesday in parts of Colusa, Glenn, Lake, Sutter, Tehama and Yolo counties.

The utility said shutoffs are also likely in parts of Napa, Solano and Sonoma counties through Thursday. Parts of the Cortina and Grindstone Rancherias could also be affected.

As of 1:30 p.m. Wednesday, shutoffs had begun in Colusa and Glenn counties.

In all, PG&E said the targeted shutoffs are expected to affect just under 5,000 customers.

The red flag warning will be in effect through 5 p.m. Thursday.

PG&E last implemented power shutoffs in mid-May across a swath of Northern California.