GRASS VALLEY (CBS13) – Another PG&E power shutoff is beginning to take effect across Northern California, leaving more than half a million customers in the dark.

The utility, which was still working to restore power following a weekend outage, will pull the plug on nearly 600,000 customers starting Tuesday morning.

PG&E says powerful winds will kick up and make for some dangerous fire conditions.

Portions of 30 counties will lose power, including El Dorado, Placer, Nevada and Solano.

Some customers who lost power during the weekend outage may not get it back before this shutoff.

The following school districts have canceled classes on Tuesday due to the power shutoffs:

-Black Oak Mine Unified School District

-Calaveras Unified School District

-Camino Union School District

-El Dorado Union High School District (only El Dorado and Ponderosa high schools)

-Gold Oak Union School District

-Gold Trail Union School District

-Grass Valley School District

-Marysville Joint Unified School District

-Placerville Union School District

-Pioneer Union School District

-Pollock Pine Elementary School District

-Yuba County School District