The Lightning Fires of August

PUBLISHED OCT 27, 2020 12:00 A.M.
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The first wave of lightning lit up the Bay Area's late night sky on Aug. 15, 2020.

The first wave of lightning lit up the Bay Area's late night sky on Aug. 15, 2020.   Kartik Ramanathan   CC BY-NC-ND 2.0

Beginning August 15, news platforms across the state and country released a cacophony of headlines characterizing California’s exceptional wildfire season. “Raging blazes,” “lighting sieges,” and “record temperatures” splashed across online front pages and Twitter feeds for several weeks to ensure that readers understood the novelty of the infernos that followed 72 hours of dry lightning strikes.

For a decade or more, California has been experiencing more dangerous and devastating fire seasons that earn sobering national coverage. The state’s rapid population growth, urban development, and need for forest management came to a head in 2017 when 9,270 blazes consumed 1.54 million acres across the state resulting in record fatalities. From then, a new wave of discussion around the state’s long fiery history began in the national media alongside regulation and legislation proposals. Persistent drought and rising temperatures due to climate change are universally cited.

In November of 2018, sparks from Pacific Gas and Electric Company wires struck Butte County’s arid late fall landscape like a match, igniting the infamous Camp Fire. Immediately following the Camp Fire, the California legislature passed and Gov. Gavin Newsom signed 22 wildfire-related laws in the 2019 session to protect citizens and forests from future blazes.

The raft of bills mostly focused on systematic blackouts, as well as prescribed burns and other forest-management practices to prevent wildfire. One blackout strategy, contained in Napa Democratic Sen. Bill Dodd’s Senate Bill 1090, required that state officials work with high-risk communities to upgrade homes in hopes of enforcing stricter fire safety codes. North Coast Democratic Sen. Mike McGuire’s Senate Bill 560 addressed strategic protocol for first responders and backup power in the event of enforced blackouts for those who rely on medical or life support equipment.

Sen. Cathleen Galgiani (D-Stockton) established a deadline for the environmental review of Cal Fire’s Vegetation Management program. That law is intended to push city utility companies to clear trees from power lines. Assembly Bill 1054, reportedly pushed by Wall Street interests, created a $21 billion state-funded reserve to protect energy companies against losses in the event of another powerline-sparked blaze. It also established recovery funds for the companies to pay out to affected customers.

In theory, these bills along with many others intended to get ahead of future wildfire seasons and their subsequent costs. But 2020’s fires were not predicted in 2019’s planning.

Lightning Strikes

The lighting started when hot, dry air collided with tropical weather systems from Mexico’s Pacific coast, sparking 12,000 lightning strikes in 72 hours. The web of bolts came without rain, and winds up to 70 mph picked up the torches and hurled them into full-fledged conflagrations.

The 2019 bills addressed one aspect of the wildfire challenges in California: man-made fire mitigation. However, they failed to account for the increasingly erratic weather patterns predicted by climate scientists, who continue to wave their warning flags in smoke-filled skies.

According to reports, the August fires indicate several significant climate patterns have converged. First, as the Los Angeles Times noted, dry heat waves were lasting longer and hitting harsher temperatures. Death Valley recorded 130 degrees on the days following the start of the fires. Triple-digit temperatures hit California almost every summer, but the last time the valley encountered temperatures like those recorded on Aug. 17 was July of 1913.

Heat waves are brought to California and the Southwest by a high-pressure weather system that hovers for several days, pushing hot air down and trapping it closer to the ground. The collision of cool Pacific water and the hot, high-elevation air typically creates summer fog that provides lower temperatures and moisture on the coastline, but little rain statewide. The exceptional heat wave of August 2020 was met with warmer coastal temperatures from Tropical Storm Fausto, a system from Baja California. According to the Mercury News in San Jose, Fausto was responsible for warm, humid air. It generated some of the first thunderstorms the state encountered, and eliminated the central and northern coast’s natural cooling mechanism.

Heat generates summer thunderstorms, which are described as rain showers accompanied by lightning. During the hot season, moisture from the ground evaporates faster in an “updraft.” Warmer droplets from the lower atmosphere collide with cooler ones from the upper atmosphere and generate electricity. Much of that is contained in the clouds, but when the pressure builds up too much, it surges downward toward neutral ground. We see this as the spectacle of lighting. The speed at which this happens breaks the sound barrier—thus thunder.

During moderate temperature conditions this phenomenon generates rain and can produce flash floods. But persistent droughts and extreme heat create dry lightning.

When temperatures between the ground and the storm system are in triple digits and the thunderstorms are at high elevation, the rain evaporates before it hits the ground. When the lightning collides with the earth it scorches the ground at 50,000 degrees Fahrenheit, unaccompanied by water. Amid this perfect storm, the evaporation of moisture on its downward trajectory generates winds that fuel an uncontrollable spread from the combustion outward.

By the end of the month California lost 1.7 million acres to the wildfires.

Tracking the Trend

Dry lightning is not unprecedented in California, as reported by the Los Angeles Times. 640,000 acres burned during the lightning “Siege of ’87.” In 1999, 86,700 acres burned in the Kirk Complex at Big Sur’s coastline, sparked by another series of strikes. And in June of 2008, 33 hours of lightning started 4,923 fires and burned 1,593,690 acres.

None of these lightning sieges came close to the number of strikes, or the magnitude of destruction, seen in August of 2020.

Coincidentally, the winter of 2019-2020 also saw record low levels of precipitation, setting the summer up for a spread of dry tinder throughout grasslands and forests. The absence of winter rains made the underbrush and landscape particularly volatile. Meteorologist Cindy Palmer, in the Bay Area office of the National Weather Services, told Bettina Boxall of the LA Times that the lightning itself wasn’t that unusual. She explained that storms like this carry their moisture in the higher atmosphere, and the August lightning storm simply did not produce enough moisture to temper the high ground heat and put out the fires.

All prior knowledge understood, on the morning of Aug. 31, Cal Fire updated the public with data comparing the 2020 season to 2019. From Jan. 1 to Aug. 31 of 2019, the state saw 4,600 fires which collectively burned 63,000 acres. From Jan. 1 to Aug. 31 of 2020, Cal Fire recorded 7,300 fires and 1.7 million acres burned. As the state neared a new record, firefighters grappled with 18 large active fires. In one week they had reduced the number from 24, but the incessant burning tested the manpower of California’s fire force and initiated panic among elected officials to ramp up fire season preparations.

During August’s wildfires, California’s elected Democratic officials quickly initiated Assembly Bill 1659 for immediate release of $500 million allocated toward additional wildfire preparation, training, and supplies. The bill also included up to $3 billion for wildfire prevention in the upcoming year. Representatives felt immediate pressure to reallocate the state surplus in order to ride out the remainder of the wildfire season and gear up for the next year. The bill would have required Newsom to waive the 72-hour notice period for it to be considered on the floor before the end of 2020’s legislative session. As of Aug. 28, the bill was recorded “Amended.”

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