By Paul Elias
3 August 2018

SAN FRANCISCO (Associated Press) – A deadly Northern California wildfire burned so hot in dry and windy conditions that it birthed a record-breaking tornado of flame, officials said Friday.

They also warned of worsening conditions throughout the region.

Winds in the "fire whirl" created 26 July 2018 near Redding, California, reached speeds of 143 mph, a speed that rivaled some of the most destructive Midwest tornados, National Weather Service meteorologist Duane Dykema said. The whirl uprooted trees and tore roofs from homes, Dykema said.

The whirl measured a 3 on the five-level Enhanced Fujita scale, which scientists use to classify the strength of tornados, he said. California has not recorded a tornado of that strength since 1978.

That fire continues to burn about 100 miles (160 kilometers) south of the Oregon border as firefighters there and throughout Northern California brace for worsening conditions this weekend. […]

Forecasters said areas with the highest threat include the massive blaze near Redding and two fires burning next to each other around Clearlake about 100 miles (160 kilometers) north of San Francisco.

The Redding fire has grown to 206 square miles (533-square-kilometer) and has destroyed 1,060 homes and many other structures. [more]

Northern California wildfire created destructive tornado


By Matthew Cappucci
3 August 2018

(The Washington Post) – A tornado? Scary. Wildfire? Horrific. A tornado made out of fire? Just about the most terrifying thing Mother Nature can whip up.

On July 26, the Carr Fire near Redding, Calif., unleashed a vortex with winds so strong it uprooted trees and stripped away their bark. On Thursday, the National Weather Service estimated the fire-induced tempest packed winds in excess of 143 mph. Such wind strength is equivalent to an EF3 tornado, on the 0-to-5 scale for twister intensity.

“This is historic in the U.S.,” Craig Clements, director of San Jose State University’s Fire Weather Research Laboratory, told BuzzFeed News. “This might be the strongest fire-induced tornado-like circulation ever recorded.”

The tornado formed as the blaze, which has already charred an area three times as large as the District of Columbia, erupted and began to rotate like a supercell thunderstorm. Initially the smoke plume reached about 20,000 feet. That’s not overly impressive for a thunderstorm, but it couldn’t rise any higher: It was trapped beneath an inversion.

That “cap” in the atmosphere caused the smoke to spread out. But around 7:15 p.m. Pacific time, two plumes suddenly managed to break the cap. They rose into an unstable environment and exploded upward, towering to nearly 40,000 feet within 30 minutes. That extreme, rapid vertical growth of the fire fueled an updraft that eventually would spawn the tornado. […]

The key was how quickly the updraft rose. After all, the smoke cloud top doubled in height, surging upward nearly four miles in 40 minutes. Just like a skater pulling in her arms, when a vortex near the ground is stretched, it intensifies — likely the main ingredient in tornado formation. [more]

California’s Carr Fire may have unleashed the most intense fire tornado ever observed in the U.S.


A high-tension power transmission line tipped over from a tornado-like fire vortex that reached speeds of possibly more than 143 mph on 26 July 2018. Photo: Cal Fire / National Weather Service

By Rong-Gong Lin II , Joseph Serna, and Louis Sahagun
3 August 2018

(Los Angeles Times) – As authorities sifted the rubble from the fire that burned more than 1,000 residences in Shasta County, they were startled by what they encountered.

A soaring transmission tower was tipped over. Tiles were torn off the roofs of homes. Massive trees were uprooted. Vehicles were moved. In one spot, a fence post was bent around a tree, with the bark on one side sheared off.

This was not typical wildfire damage. Rather, it was strong evidence of a giant, powerful spinning vortex that accompanied the Carr fire on July 26. The tornado-like condition, lasting an hour and a half and fueled by extreme heat and intensely dry brush as California heats up to record levels, was captured in dramatic videos that have come to symbolize the destructive power of what is now California’s sixth-most destructive fire.

It may take years before scientists come to a consensus on what to exactly call this vortex — a fire whirl, as named by the National Weather Service, or a fire tornado. Whatever it’s called, it’s exceptionally rare to see a well-documented fire-fueled vortex leap out of a wildfire and enter a populated area with such size, power and duration.

It’s believed to have lasted from 7 p.m. to 8:30 p.m. on July 26 and struck some of the hardest-hit neighborhoods in Redding.

A pyrocumulus cloud over Californ'a Carr Fire on 29 July 2018, generated when the fire is so hot the air explodes upward, creating a new local weather pattern that can bring strong winds, lightning, and new fires. Photo: Truckee Meadows Fire Protection District

This kind of fire twister has been documented before, but only a handful “at this sort of scale,” said Neil Lareau, assistant professor of atmospheric sciences at the University of Nevada, Reno, who was among those comfortable calling it a fire tornado. “You’re starting with a rare event to begin with, and for it to actually impact a populated area makes it even rarer.”

The National Weather Service on Thursday said a preliminary estimate of maximum wind speeds in the vortex were in excess of 143 mph. That would make it equivalent to a twister with a rating of EF-3 out of a maximum of 5 on the Enhanced Fujita scale.

“Depending on the final number, this might actually be the strongest ‘tornado’ in California history, even if it wasn’t formally a tornado,” UCLA climate scientist Daniel Swain said by email. There have been a couple of marginal EF-3 twisters in California’s past, “but this fire whirl was almost certainly longer-lived, larger in spatial scope and perhaps even stronger from a wind speed perspective.”

The vortex could be a factor in the deadly ferocity of this blaze, which killed six. And with climate change playing a factor as California enters a worsening era of wildland fires, last week’s fire vortex adds a layer of unpredictability and danger.

“Not all big fires are going to result in these big fire whirls, even in a future that’s much hotter and drier,” Swain said. “This won’t be the primary risk associated with wildfire, ever. But under the right atmospheric conditions, all else being equal, the increasing intensity of fires themselves will play a role in producing these localized fire weather conditions that can be quite extreme.”

Radar analyzed by Lareau clearly shows a spinning vortex in northwest Redding as the Carr fire rapidly expanded in the evening of 26 July 2018.

Radar shows a spinning vortex in northwest Redding as the Carr fire rapidly expanded in the evening of 26 July 2018. Data from Neil Lareau / University of Nevada, Reno. Graphic: Lorena Elebee / Los Angeles Times

Lareau roughly estimated the vortex as being as perhaps 500 yards in diameter at its base before possibly contracting. “It’s covering blocks,” he said.

“It was definitely a massive one, and that just speaks to how intense the heating was,” said National Weather Service meteorologist Mike Kochasic. “It created such a massive whirl that it looked like a tornado … and it takes an impressive amount of heating and local wind swirling up to create something like that. It was quite a monster.” [more]

143-mph 'fire tornado' that cut a path of destruction is an ominous sign of the future

0 comments :

 

Blog Template by Adam Every . Sponsored by Business Web Hosting Reviews