Large fire whirl on Gorman Fire

This is a very impressive large fire whirl over the Gorman Fire Friday in Los Angeles County, filmed by Kevin Takumi for FoxLA.com

The images are screenshots from Mr. Takumi’s video.

fire whirl gorman fire

Fire whirls at Burning Man

Kevin sent us a link to a very interesting video that was shot at Burning Man. It shows fire whirls and dust devils that, according to the Reno-Gazette Journal, appeared “as the Catacomb of Veils art installation [was] set on fire Friday, Sept. 2, 2016”. We can’t embed it, but you can check it out at the RGJ. The dust devils formed downwind of the intense fire, consistently and repeatedly. They form, move with the wind, dissipate, and then are replaced.

That piqued our interest so we looked around on YouTube to see if there were any more, and there’s a boat load of them. They have been occurring for years at Burning Man. Check them out HERE.

The image below is a screenshot from the video that follows it.

Burning  Man Fire Whirls
Screen shot from the video by r. E V O L U T I O N Art

Our definitive article about fire whirls, dust devils, and fire tornadoes.

Thanks and a tip of the hat go out to Kevin.

Fire whirl on Beaver Creek Fire two months after the fire started

fire whirl beaver creek fire
Fire whirl on Division G of the Beaver Creek Fire August 15, 2016. Photo by Charles Bolt, Engine 1419.

Firefighter Charles Bolt took this impressive photo of a fire whirl on the Beaver Creek Fire. It was tweeted by the Medicine Bow-Routt National Forests and Thunder Basin National Grassland.

More information about fire whirls, fire tornados, fire devils, firenados, and fire storms.

Since the Beaver Creek Fire started on June 19, 2016 it has burned over 36,000 acres in northern Colorado and southern Wyoming. It is being managed by the Atlanta National Incident Management Organization (NIMO). The team described their strategy:

This is a full suppression fire utilizing both ground and aerial assets. Firefighters are engaging the fire out of the timber in areas which give them the highest probability for success. This suppression strategy provides for both firefighter safety and the protection of life and property.

After almost two months, the team claims 44 percent of the perimeter has been contained. They expect full containment on October 21 (the year was not specified). It sounds like they may be stretching the definition of “full suppression”. So far they have spent $20,600,000 of taxpayers’ money.

Here is another photo from the fire. Found on InciWeb, it is undated and uncredited.

Beaver Creek fire saved structure

Defining fire whirls and fire tornados

These two recently filmed videos illustrate what can happen over a fire when thermal instability and available vorticity combine.

The Cornelius (Oregon) Fire Department posted this video on August 12, 2016 showing an impressive fire whirl.

The video below was filmed by Stewart Turner August 5, 2016 on the Pioneer Fire in Idaho. You will see a definite rotation, or convection column vortex. While this one is not as violent as, say, a conventional tornado, the change in wind direction or the collapse of the column can cause a serious problem for nearby firefighters.

The news media sometimes calls any little fire whirl a “fire tornado, or even a “firenado”. We found out today that these and related terms (except for “firenado”) were, if not founded, at least documented and defined in 1978 by a researcher for the National Weather Service in Missoula, David W. Goens. He grouped fire whirls into four classes:

  1. Fire Devils. They are a natural part of fire turbulence with little influence on fire behavior or spread. They are usually on the order of 3 to 33 feet in diameter and have rotational velocities less than 22 MPH.
  2. Fire Whirls. A meld of the fire, topograph, and meteorological factors. These play a significant role in fire spread and hazard to control personnel. The average size of this class is usually 33 to 100 feet, with rotational velocities of 22 to 67 MPH.
  3. Fire Tornadoes. These systems begin to dominate the large scale fire dynamics. They lead to extreme hazard and control problems. In size, they average 100 to 1,000 feet in diameter and have rotational velocities up to 90 MPH.
  4. Fire Storm. Fire behavior is extremely violent. Diameters have been observed to be from 1,000 to 10,000 feet and winds estimated in excess of 110 MPH. This is a rare phenomenon and hopefully one that is so unlikely in the forest environment that it can be disregarded.

Mr. Goens further described three different types of fire whirls generated:

  1. The Thermally Driven Form. This results from some type of shear in the horizontal airflow coupled with the energy release (convection) from fire activity.
  2. The Convection Column Vortex. This form is poorly understood. It originates high in the convection column (up to 1000 feet) and extends in the ground as much as a fourth (1/4) mile on the leeward side of the fire.
  3. The Wake-Type Whirl. This results from the generation of eddies caused by airflow around an obstacle coupled with heat released by the fire.

Mr. Gowns continued:

All three of these types can be a significant problem in the spread or control of fire. The fire whirl in its steady-state form, i.e., after it has formed and before it begins to collapse, has two sharply defined regions of differing airflow (Byron and Martin 1970). The cooler, slowly rotating zone surrounds a central core of hot gases with high horizontal and vertical velocities. This central core can have temperatures from 1,800° to 2,400°F and burning rates two to seven times normal. Flame height can be 10 to 50 times the core diameter. Fire spread occurs when burning debris entrained into the column just above the surface boundary layer is carried aloft and then cast out from the upper portion of the whirl core some time later. The path of the whirl can be quite erratic; therefore, direction and rate of spread are almost impossible to forecast.

One of the best videos of a large fire whirl or fire tornado was shot by Chris Tangey of Alice Springs Film and Television in 2012 while he was scouting locations near Curtin Springs station in Australia. It is used here with his permission.

And lastly, I filmed this next video at the USFS Fire Lab in Missoula in 2014, showing an artificially created fire whirl.

A few more details released about fire shelter deployment on the Cedar Fire

On Sunday the Bureau of Indian Affairs released a “72-hour report” that contains a few more details about the entrapment of six firefighters and deployment of their fire shelters on the Cedar Fire south of Show Low, Arizona.

The new information includes mentions of a large fire whirl and three lookouts that were posted.

Below is the press release version of the 72-hour report. The formal memo-style document is HERE. They contain approximately the same information.

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“On June 28, a large fire whirl formed near six members of the Navajo Interagency Hotshot Crew (IHC), entrapping them. In response to the intense heat, flying ash and woody debris, the firefighters deployed their fire shelters.

Throughout the 15 minute event, the crew maintained radio communication with each other and agency personnel. Aviation and safety resources were immediately dispatched to assist the crew.

After the fire whirl passed, the IHC walked out of the fire area and were transported to Summit Healthcare in Show Low, Arizona. Two firefighters were treated for smoke inhalation and all six firefighters were released from the hospital that evening. After the crew was released, a Critical Incident Stress Management Team was made available to the crew.

The Bureau of Indian Affairs initiated an Interageny Serious Accident Investigation (SAI) that evening. On June 30, the SAI Team members, led by Clark Richins, Team Leader, Bureau of Indian Affairs, reported to Western Region, Fort Apache Agency. Members of the SAI Team include: Chief Investigator, Safety Officer, Personal Protective Equipment Specialist, Long Term Fire Analyst, Hotshot Crew Representative, Public Information Officer, Writer/ Editor, and Regional and National Agency Liaisons.

The investigation will collect evidence, which includes conducting personnel interviews, inspecting equipment and analyzing photographs, weather and voice data. On June 30, the SAI Team completed their interviews of the IHC, which allowed the crew to return home.

According to the National Wildfire Coordinating Group Terminology Glossary, a fire whirl is a spinning vortex column of ascending hot air and gases rising from a fire and carrying aloft smoke, debris, and flame. Fire whirls may range in size from less than one foot to over 500 feet in diameter and have the intensity of a small tornado.

Prior to the event, the crew was working along the western flank of the uncontained fireline where they had previously been assigned for several days. At 12:00p.m three nearby lookouts observed low intensity surface fire, but by 2:00p.m., as the day got warmer, the fire behavior increased. These lookouts and an additional firefighter scouting the fireline witnessed the large fire whirl.

While managing wildland fires is inherently dangerous, all firefighters are trained to minimize the risk they take on every assignment. In the rare circumstance firefighters are faced with an impending entrapment, they are trained to consider all options to insure the safety of all crew members. This includes deploying fire shelters for protection from smoke, heat, and embers. The Navajo Interageny Hotshot Crew executed their training, which resulted in a successful outcome to a hazardous wildfire anomaly.

As a highly reliable organization, the wildland fire community strives to learn and transfer lessons learned on a continual basis. In the spirit of this culture, the BIA Western Region will provide the Factual Report to the Lessons Learned Center when the Report is finalized.”

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Thanks and a tip of the hat goes out to Jonah.