Dry vegetation and high winds were a major factor in PG&E shutoff
The morning of Oct. 8, Humboldt County residents were notified that Pacific Gas & Electric may shut off power county-wide. HSU students and faculty began rapidly preparing for the possible outages, but some wondered what forced the utility giant to turn off the power.
Leading up to the blackout, rumors spread as people speculated why PG&E decided shutting off power was the best option, and others wondered how long the outage could last. It seemed there was a lack of communication, as only some local professionals seemed to know the details.
On the night of Oct. 9, HSU Facilities and Management employee Brian Wheeler was responsible for filling up HSU’s generator. The diesel generator was the only thing standing between powerless students and the cold, dark night.
Wheeler said he had heard about an algorithm PG&E made to inform them when to shut off the power. This was confirmed by Megan McFarland, a spokesperson for the company. McFarland said no single factor drives a Public Safety Power Shutoff since each situation is unique.
PG&E carefully reviews many criteria when determining if power should be turned off for safety. These factors generally include, but are not limited to:
- A Red Flag Warning declared by the National Weather Service.
- Low humidity levels, generally 20% and below.
- Forecasted sustained winds above 25 mph and wind gusts in excess of approximately 45 mph, depending on location and site-specific conditions such as temperature, terrain and local climate.
- Condition of dry fuel on the ground and live vegetation (moisture content).
- On-the-ground, real-time observations from PG&E’s Wildfire Safety Operations Center and observations from PG&E field crews.
To get a better grasp on the situation and its factors, The Lumberjack contacted the Woodley Island National Oceanic and Aeronautic Administration. Meteorologist Jeff Tonkin understood the specifics and why PG&E could be forced to make such a decision, but believed that Humboldt County wasn’t initially a part of the plan for a reason.
“PG&E shuts down based on wind speed if it is projected to cause a disruption or a failure,” Tonkin said. “Locally in Eureka, the power wasn’t shut down because of local high winds. We’re just collateral damage.”
Tonkin said NOAA had meetings with PG&E meteorologists in the past, but PG&E doesn’t consult NOAA for weather information. While getting in contact with one of PG&E’s scientists would likely be key to understanding why the power was shutoff officially, Deanna Contreras, another PG&E spokesperson, answered the call instead.
Contreras said, for this particular shutoff, the weather patterns were somewhat unique and widespread. Many forecasters compared the conditions to the devastating conditions from October 2017.
In response to the rapidly changing environmental conditions in our state, beginning with this year’s wildfire season, PG&E expanded its Public Safety Power Shutoff program to include all electric lines that pass through high fire-threat areas – both distribution and transmission.
Cotreras said there weren’t any PG&E meteorologists available but had plenty of details about PG&E’s weather system.
“Beyond PSPS information, weather geeks will find a lot to love about the new weather page,” Contreras said. “With PG&E’s weather map at your fingertips you’ll be able to check humidity, precipitation, temperatures, wind speeds and wind gusts across 70,000 square miles of Northern and Central California.”
Contreras said the page offers a seven-day regional forecast. PG&E’s Wildfire Safety Operations Center team monitors all these conditions and evaluates whether to proactively turn off electric power lines, in the interest of public safety, if extreme fire danger conditions are forecasted.
McFarland said a lot of PG&E employees live and work in regions that are affected by the shutoff and that she understands how frustrating it is to have the power turned off. She said the decision was not made lightly.
“We want customers to know that although you may not live or work in a high fire-threat area,” McFarland said, “Your power may be shut off if the line serving your community relies upon a line that runs through an area experiencing extreme fire danger conditions.”