Bomb cyclone slams Pacific Northwest causing over 600,000 power outages

Strong winds from a bomb cyclone caused widespread power outages across the Pacific Northwest, and utilities said Nov. 20 restoration could take several days.

Back-to-back powerful storms are expected to hit the West Coast this week with heavy rain, flooding, strong winds and high elevation mountain snow, the National Weather Service's Weather Prediction Center said Nov. 20.

"A significant Pacific storm system and strong atmospheric river have already started pummeling the West Coast and Northwest this morning," the weather service said in its Nov. 20 forecast discussion. "The very deep low-pressure system churning about 300 miles off the coast of Washington is responsible for high winds impacting much of northern California, Oregon, and Washington. These winds have already produced numerous power outages, reports of tree damage, and are expected to create blizzard conditions throughout the Cascades."

Wholesale spot power prices across the Pacific Northwest averaged roughly 50% higher than the month-to-date average on Nov. 20.

Mid-C on-peak day-ahead traded around $48/MWh for Nov. 21 delivery on the Intercontinental Exchange, which was 56% above the to-date November average from Platts pricing data and 80.5% higher than prices a week ago.

Platts is part of S&P Global Commodity Insights.

Likewise, COB on-peak day-ahead traded around $48.25/MWh for Nov. 21 delivery on ICE, 43% higher than the Platts-assessed month-to-date average and 72% higher week on week. In Northern California, NP15 on-peak day-ahead traded at $61/MWh for Nov. 21 delivery on ICE, 48% above the to-date November average and 23% higher week on week compared to pricing data from the California Independent System Operator.

Meanwhile, spot prices were lower week on week in Southern California and across the Desert Southwest.

Power outages

There were nearly 550,000 outages in Washington state as of 7:30 am PT Nov. 20, with under 30,000 outages in Northern California, according to poweroutage.us. The majority of outages were in the Puget Sound Energy service territory, with over 400,000, followed by Snohomish County Public Utility District with about 73,000 and Seattle City Light with nearly 60,000.

Puget Sound Energy peaked at around 422,000 outages overnight, with 120,000 restored overnight, she added.

"We know we have significant damage to our transmission system, but are still assessing the damage," Coon said. "We have helicopter patrols going in the air and crews on the ground throughout our service area doing damage assessment to understand the extent of the damage. These assessments help us determine the estimate time of restoration."

The utility expects a multiple day outage, Coon said, adding crews were staged in advanced at key areas of the service area to help with restoration quickly.

Snohomish County PUD also expects restoration could take multiple days.

"Overnight we experienced high winds caused by a bomb cyclone off the Washington coast," Snohomish County PUD spokesperson Kellie Stickney said Nov. 20. "Parts of the Snohomish County PUD service territory experienced gusts of wind upwards of 60mph. Winds, combined with saturated soil, toppled numerous trees across the region and brought down poles and wires."

Restoration is being slowed by downed trees, making access to complete repairs very difficult, Stickney said, adding the utility experienced damage to equipment and transmission lines due the storm.

Seattle City Light peaked at around 114,000 outages at 11 pm PT Nov. 19, spokesperson Jenn Strang said Nov. 20.

"Most outages were caused by high winds or falling trees, limbs and debris," Strang said, adding crews are working around the clock on restoration efforts. "We did have some impacts to our infrastructure, but staff and crews will be assessing the damage and making any necessary repairs throughout the day."

This was the largest storm in terms of the number of customers impacted since the 2006 Hanukkah Eve storm, she added. Seattle City Light restored power to nearly 29,000 customers overnight, the utility said in a tweet.