The tower of billowing cumulus clouds and smoke rising above Northern California’s Carr fire said it all. The flames jumping around Redding’s western edge had created their own micro weather system, tossing fire brands helter-skelter across the baking landscape.
California’s big, destructive wildfires tend to come in two varieties: wind-driven, such as last year’s deadly Santa Rosa conflagration and December’s Thomas fire in Southern California. And what is known as plume-dominated, when a fire’s plume of smoke and ash is big and hot enough to exert control.
Wind gusts were a factor in the Carr, which destroyed 65 residences on Redding’s edge, sent panicked homeowners fleeing in the middle of the night and caused the deaths of a city firefighter and a bulldozer operator. But fire experts say the explosive growth of the Carr was more a function of extreme heat and dried-out fuels that stoked flames intense enough to generate their own weather.
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“This is not what I would call a wind-driven fire,” said U.S. Forest Service meteorologist Tom Rolinski. “It’s more of a plume-dominated fire. It creates a lot of erratic fire behavior.”
The quickly moving blaze jumped the Sacramento River and raced in different directions, creating fire whirls and making it impossible to control. “It was moving all over the place,” said Mike Mohler, deputy communications director for the California Department of Forestry and Fire Protection.
Redding is a city of 90,000 people hugging the Sacramento River on one side and a landscape of oak trees, grasslands and chaparral. Cal Fire officials said the burned homes were outside of town and on the city’s edge — an interface of flammable wildlands and buildings that over the years have been the scene of the state’s deadliest fires.
As is often the case when flames encroach on developed neighborhoods, photos from the Carr fire showed houses in smoldering ruins while nearby trees appeared untouched by flames — evidence that flying embers set the buildings on fire rather than an advancing wall of flames.
While fierce winds that have driven many of the state’s biggest blazes — such as Santa Barbara’s sundowners and Northern California’s diablos — were not a key factor in Redding, other ingredients that fuel big fires were abundant.
Always brutally hot in the summer, the area was hit by record-breaking temperatures this week. Thursday it was 113 degrees.
“The summertime temperatures have been really extreme,” said Dave Sapsis, a state wildfire specialist.
The heat not only sucks the moisture out of live plants, it also further dries out dead limbs and brush. And the combination of the state’s punishing five-year drought, followed by record Northern California rains in 2017, left plenty of fuel. An ignition and the right weather conditions are all that is needed to send flames racing over the hills and up canyons.
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Cattle graze on the grassland near the Ranch fire outside of Lodoga.
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A man fishes in Clear Lake as the smoky haze shrouds visibility in Clearlake Oaks.
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A plume of smoke rises from the Mendocino Complex fire near Lodoga. The Mendocino Complex Fire, which is made up of the River Fire and Ranch Fire, has surpassed the Thomas Fire to become the largest wildfire in California state history with over 300,000 acres charred.
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Firefighters battling the Mendocino Complex blaze monitor a burn operation on top of a ridge near the town of Ladoga on Aug. 7.
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Crews battling the Mendocino Complex fire supervise a burn operation near the town of Ladoga on Aug. 7.
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Firefighters keep an eye on a burn operation as part of the battle against the Mendocino Complex blaze on Aug. 7.
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Arnold Lasker looks over the remains of his girlfriend’s house in Spring Valley, near Clearlake Oaks, on Aug. 7.
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Evacuated during the Ranch fire, Jay Michael and Gretchen Fritsch rest in their car in the parking lot of the Moose Lodge in Clearlake Oaks on Aug. 7. This is the eighth time they have been evacuated since living in the area, and the third time this year.
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Burned out cars sit in the remains of a home that was destroyed by the Medocino Complex fire in Clearlake Oaks, Calif.
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A sign warns people to stay out of a burned area in Clearlake Oaks, Calif.
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Helicopters enroute to pick up water at the Mendocino Complex fire in Clearlake Oaks, Calif.
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A Buddha statue is seen at a burned home in Spring Valley, near Clearlake Oaks, Calif.
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Image taken from the International Space Station shows the wildfires burning in Calif. In the upper left portion of the image is the Carr and Mendocino Complex fires and to the right is the Ferguson fire. (ALEXANDER GERST / AFP/Getty Images)
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Resident Lane Lawder carries a water bucket while fighting to save his home from the Ranch fire burning along New Long Valley Road near Clearlake Oaks.
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A tree burns from the inside during the Ranch fire in Clearlake Oaks.
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An air tanker drops retardant on the Ranch Fire, part of the Mendocino Complex Fire, burning along High Valley Rd near Clearlake Oaks.
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A fire truck passes a vineyard while battling the Ranch Fire, part of the Mendocino Complex Fire, near Clearlake Oaks.
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A hillside smolders after flames passed through during the Ranch fire in Clearlake Oaks.
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The Ranch fire burns a home on New Long Valley Road near Clearlake Oaks on Saturday.
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A firefighter gathers water from a pool while battling the Ranch Fire near Clearlake Oaks on Saturday.
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A deer flees as the Ranch fire tears down New Long Valley Road near Clearlake Oaks on Saturday.
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Dan Kissick, 60, left, shown with his son Jeff Kissick, searches the remains of his home on Kellinger Street on Saturday after the Carr fire hit Redding.
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Maureen Kissick examines china from her wedding 36 years ago as she sits in what was once the dining room of her home on Kellinger Street in Redding.
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A Pacific Gas and Electric Co. crew repairs power lines Saturday near the damaged home of Jose Briones along Baker Road in Redding.
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Smoke clouds rise from the Ranch Fire portion of the Mendocino Complex Fire in Lakeport on Aug. 1.
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Buzz Craddock carries a pack tied with antlers covered in fire retardant as firefighters work to stop the progression of the River fire in Lakeport, Calif.
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The charred remains of a truck sit in the ash in Lakeport, Calif., on Aug. 1.
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Firefighters watch as air tankers drop fire retardant ahead of the River fire in Lakeport, Calif., on Aug. 1.
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Helicopters make water drops as flames from the River fire advance towards Lakeport, Calif.
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A West Covina firefighter works as a barn in the background is destroyed by the Mendocino complex fires near Lakeport, Calif., on July 31.
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A barn is engulfed in flames as the Mendocino complex fires spread with the wind near Hendricks Road in Lakeport, Calif., on July 31.
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Chickens near a home being destroyed by the Mendocino complex fires in a neighborhood near Lakeport, Calif., on July 31.
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Firefighters work to keep flames from the Mendocino complex fires from destroying a home as evening winds kick in near Lakeport, Calif., on July 31.
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A helicopter makes a water drop near the raging Mendocino complex fires west of Lakeport, Calif., on July 31.
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Firefighters work to keep flames from the Mendocino complex fires from destroying a home as evening winds kick in near Lakeport, Calif., on July 31.
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A firefighter monitors a controlled burn along California 20 in Upper Lake on July 31. The Ranch and River fires are burning together as the Mendocino complex fires.
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Firefighters from S&R Contracting in Oregon dig into the ground as they make sure all residual flames are put out near Redding, Calif., on July 30.
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The Carr fire destroyed and sunk boats docked at the marina in Whiskeytown, Calif.
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The Carr fire swept through and destroyed property and structures in Shasta, Calif.
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A Cal Fire firefighter waters down a back burn on Cloverdale Road near the town of Igo on Saturday, July 28, 2018. The back burn kept the fire from jumping toward the town. Scorching heat, winds and dry conditions complicated firefighting efforts.
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A deer stands in the middle of a road covered in fire retardant as the Carr fire continues to threaten structures near Redding on Saturday, July 28, 2018.
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Mark Peterson, who lost his home in the Carr fire, gives water to goats that survived the blaze on Saturday, July 28, 2018, in Redding.
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Wildfire destroyed homes overnight in Lake Keswick Estates near Redding on July 27.
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A woman covers her face while viewing her grandmother’s home, burned in the Carr fire in Redding, on July 27.
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A firefighter sprays water on what’s left of a Redding home damaged by the Carr fire on July 27.
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A firefighter lights backfires during the Carr fire near Redding on July 27.
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A burning home is reflected in a pool during the Carr fire in Redding on July 27.
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A home burns along Sunflower Road in Redding during the Carr fire on July 27.
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A structure burns as the Carr fire races along State Route 299 near Redding on July 26.
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Firefighters transport a Carr fire evacuee to the Mercy Medical Center emergency room on July 26.
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Firefighters discuss plans while battling the Carr fire in Shasta County on July 26.
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Firefighters regroup while battling the Carr cire in Shasta County on July 26.
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A structure is engulfed in flames as the Carr fire burns along State Route 299 near Redding on July 26.
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A water tender operator helping to battle the Carr fire drinks a beverage after trying to save a burning structure in Shasta on July 26.
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The Carr fire burns near Shasta on July 26.
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A historic schoolhouse burns as the Carr fire tears through Shasta on July 26.
(Noah Berger / Associated Press) Summer in California is wildfire season, but Sapsis said the level of fire activity so far this month, especially in Northern California, is more typical of late August. “The entire northern part of the state has been besieged by fire for about a month now,” he said.
It’s difficult to gauge the effect of climate change on wildfires, as the reasons for more blazes include more human-caused ignitions, a history of fire suppression in the Sierra Nevada and development’s push into formerly empty wildlands.
But scientists say warmer temperatures are a factor in the growth of wildfires in the West.
“I think the warmer temperatures are making them more extreme,” said UC Merced professor Anthony Westerling.
Pyrocumulus clouds — such as the one towering above the Carr blaze Thursday — form when the atmosphere above a fire plume is unstable, usually in the heat of the afternoon.
The collapse of the clouds as temperatures drop at night creates downdrafts that can create dangerous conditions on the ground.
“The fire goes in all different directions” Rolinski said, though he did not know if that was the case with the Redding blaze.
bettina.boxall@latimes.com
