The likely Public Safety Power Shutoff (PSPS) event for Monday and Tuesday has been revised and now only shows 23 counties likely to be affected. Typically, only part of a county is affected by a PSPS, not the entire county.

According to the update, 24,667 customers will be affected – mostly on the western side of the Sacramento and San Joaquin Valleys.

The following counties are now on PSPS Watch: Alameda, Butte, Colusa, Contra Costa, Fresno, Glenn, Kern, Kings, Lake, Merced, Monterey, Napa, Plumas, San Benito, San Joaquin, San Luis Obispo, Santa Barbara, Shasta, Solano, Sonoma, Stanislaus, Tehama, Yolo. In addition to the cities and counties above, the following tribal communities have been notified of potential impact on tribal lands: Cortina Rancheria, Grindstone Rancheria, Middletown Rancheria, Mooretown Rancheria, Pit River Tribes.

The PG&E Emergency Operations Center remains activated for a potential PSPS event Monday through Tuesday and the forecast has been updated to show PSPS Watch for multiple counties. Read on for more details. A weather system will drop into Nevada tonight into tomorrow and result in the development of widespread gusty north winds and critical fire weather conditions across the PG&E territory Monday morning through Tuesday.

Northerly winds will increase tonight into early Monday morning across the northern Sacramento Valley and adjacent foothills, before spreading southward into the San Joaquin Valley and across elevated Bay Area and Central Coast terrain throughout the day.

Sustained winds are expected to reach 15-30 mph with widespread gusts in the 35-45 mph range and peak gusts of 50+ mph are possible across the Sacramento and San Joaquin Valleys, surrounding foothills and over elevated terrain of the Bay Area and Central Coast. Winds are forecast to remain gusty through late Tuesday morning before gradually decreasing throughout the day.

Relative humidity values will drop to 10-20% by tomorrow afternoon across most of the region followed by poor to moderate recovery during the overnight hours. The combination of gusty winds, low humidity and dry fuels during this time will result in critical fire weather conditions and has led multiple National Weather Service offices to issue Fire Weather Warnings across Northern California late tonight through Tuesday afternoon.

Fair, dry, and warmer weather will continue today before a potent low-pressure system moves through the territory resulting in cooler temperatures and the development of gusty northerly winds across the entire territory tomorrow morning through midday Tuesday.

Northerly winds will begin to increase across the elevated far North and northern Sacramento Valley this evening and then strengthen as they spread southward into the San Joaquin Valley and across elevated Coast terrain overnight through tomorrow morning. Winds will remain gusty during the day Monday and continue overnight through late Tuesday morning before gradually decreasing through the afternoon. Winds are forecast to reach 15-30 mph range with widespread gusts of 35-45 mph and peak gusts of 50+ mph possible across the Sacramento and San Joaquin Valleys, adjacent foothills, and over elevated Bay Area and Central Coast terrain.

Relative humidity values will decrease into the 10-20% range during the day Monday and Tuesday with poor to moderate improvement overnight. Federal forecast agencies continue to highlight the potential for critical fire weather conditions Monday and Tuesday.

Additionally, the National Weather Service has issued multiple Red Flag Warnings for much of northern and central California. Northern Operations Predictive Services has issued High Risk for a similar footprint as the National Weather Service Monday and Tuesday.

Fair and dry weather is expected Wednesday followed by another chance for offshore flow to develop late week; however, details related to strength and timing remain unclear at this time. Dead fuel moisture has improved in some areas due to recent precipitation, but overall values are still below normal across most of the territory for this time of year and the moisture content in brush and chaparral remains at or below critical levels.