From PG&E’s weather awareness page:
Summary: The PG&E Emergency Operations Center has been activated to prepare for a potential Diablo wind event lasting from Wednesday through Thursday aside from the Northern Sierra that may experience Diablo winds through Friday morning.
The current forecast shows PSPS Watch in Zones 2, 3, 4, 5, 6 and 8 for the upcoming event. Please note that PSPS is not executed across entire Zones and much more detailed maps where PSPS is being considered will be provided on PG&E’s website this evening. This forecast is only intended to provide a high level overview. PSPS decisions are made at more granular levels based on high resolution data; thus, only a portion of a zone may experience a PSPS event.
At this time, the highest probability areas for executing PSPS are the Northern Sierra Nevada foothills, the mid and higher elevations in the Sierra generally north of Yosemite (northern portion of Zone 8), the North Bay mountains near Mt. St. Helena, small pockets in the East Bay near Mt. Diablo, the Oakland Hills east of Piedmont (generally between highway 24 and Upper San Leandro Reservoir), the elevated terrain east of Milpitas around Calaveras Reservoir, as well as portions of the Santa Cruz and Big Sur mountains. This is not expected to be a widespread event in the Bay Area at this time.
The weather event is expected to begin Wednesday evening and continue through Thursday morning. A second period of winds may develop Thursday evening through Friday morning in the Northern Sierra and Zones 2 and 5 are extended into Friday.
The start of the event is more than 2 days away so event details will likely change as forecast models evolve. We will have more clarity on potential cities and counties impacted in the next 24 hours. Please stay tuned to future updates.