September 5, 2020 – PG&E has updated the potential for a Public Safety Power Shutoff (PSPS) to a Watch potential for Tuesday and Wednesday, September 8 and 9, 2020.
At this time, no determination has been made if a PSPS will occur, however the likelihood has increased to watch level. Plan for the possibility now.
From PG&E’s forecast:
Weather models are starting to come into better agreement regarding the potential offshore wind event late Monday night through Wednesday morning. The start of the event is still more than 2 days away, so details regarding exact strength and location of the event may change moving forward. PG&E Geographic Zones 2, 3, 4, 5, and 8 are now showing PSPS Watch Tuesday and Wednesday with Zone 9 on Wednesday. High pressure will continue to strengthen over Northern California today, bringing a potent heat wave to the territory through the holiday weekend. Away from the coast, hot and dry conditions are expected territory wide, with peak heating occurring on Sunday. Daytime highs across the inland valleys and interior will easily reach triple digits today, with peak temperatures in the 105F – 112F range, with several heat prone locations exceeding 112F. Closer to the coast, expect cooler but above-normal daytime highs in the 70s and 80s. Temperatures will decrease into the start of the week, but remain above-normal as high pressure begins to weaken, and a warm, dry, offshore flow sets up over Northern California. An upper level weather system is expected to drop south into the Great Basin on Monday, and set the stage for offshore winds, primarily across the northern half of the territory. These offshore winds are expected to develop directly on the heels of the weekend heat wave, which exacerbate fuel dryness to near critical values. A return of the sea breeze and more typical late summer weather is forecast for the middle and latter part of next week, with continued above normal temperatures across the interior. The National Weather Service has issued several Fire Weather Watches across the territory, which are likely to be upgraded to Red Flag Warnings as the event gets closer. The latest National Interagency Fire Center wildland fire potential outlook favors above normal significant wildland fire potential for most of Northern CA through October as fuel moisture values are at critical levels in most areas and dead fuel moisture values are near seasonal minimums.
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.