advertisement

October 12, 2020 – PG&E’s weather center has upgraded the possibility of a power shutoff to Watch status. The event is still 2 days out and outages are not confirmed at this time. Even if a zone is on the watch list now, not all of the zone may experience a PSPS. Please stay tuned for updates, but be prepared for an outage due to the forecasted wind event.

“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. 

View a high-resolution map of the PG&E Geographic Zones (PDF, 1.7 MB)PDF. Opens in new Window.

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.

Details: A warming and drying trend is expected this week as high pressure builds in across the state. Temperatures will reach the mid to upper 80s away from the coast today with light offshore winds generally below 20 mph. Temperatures will continue to rise through the middle of the week with daytime highs in the upper 80s and 90s for most areas by Thursday.

On Wednesday, breezy northerly winds will develop through the Sacramento Valley during the day and will shift to the north/northeast Wednesday night and continue into Thursday or Friday across the northern interior. The strength of these winds remains somewhat uncertain, but gusts at or above 50 mph are looking possible in elevated terrain in the North Bay and Northern Sierra. Lighter winds return this weekend along with cooler conditions near the coast. Fire danger will rapidly increase mid to late this week as dead fuels quickly dry out under warmer and drier conditions and offshore winds. The latest National Interagency Fire Center wildland fire potential outlook continues to favor above normal large wildland fire potential for most of Northern CA for October followed by normal large fire potential for November and December.

Please note: This forecast is published daily by an operational meteorologist from PG&E’s Meteorology and Analytics team. This forecast has been customized for PG&E utility operations and should not be used for any other purpose or by any other entity. This forecast only provides a broad overview for a potential Public Safety Power Shutoff (PSPS) event in the next 7 days as determined from an analysis of forecasted weather, the potential for wind-related damage, and fuel moisture content in dead and live vegetation. It is not a fire danger forecast. The forecast is broken down by broad PG&E Geographic Zones numbered 1 – 9; however, PSPS decisions are made at more granular levels; thus, only a portion of a zone may experience a PSPS event. While a PSPS event may not be expected for an area, due to the interconnectivity of the grid any location within PG&E territory may be subject to PSPS event.”