Analysis of wind, vegetation, and air tankers before the fire burned into Gatlinburg


Above: Air Tanker 162, an RJ85, at Chattanooga, Tennessee November 27, 2016. Photo by Antonio More’. Other photos he took that day are at SmugMug.

Earlier at Wildfire Today we examined the information that the National Park Service released about the Chimney Tops 2 Fire that burned into Gatlinburg, and analyzed the day to day conditions at the fire. Today we will look further into the wind, the Energy Release Component, and the air tankers that were staged in the area but not used on the fire.

Air Tankers at Chattanooga

The fire started on November 23, 2016. On November 27, two days before the fire burned into Gatlinburg killing 14 people, destroying 2,013 homes and 53 commercial structures, and causing more than $500 million in damage, there were three large air tankers parked at Chattanooga, Tennessee, 105 miles southwest of the fire; two RJ85’s and one C-130Q. But the air tankers were not used on the fire.

Air Tanker 131
Air Tanker 131 (in the foreground) a C-130Q, and two RJ-85 air tankers, at Chattanooga, Tennessee November 27, 2016. Photo by Antonio More’.
The only aircraft used before the fire burned into the city was a helicopter in the afternoon of November 27, which was replaced a few hours later by two other helicopters. They were refilling their water buckets at Fontana Lake. The 26-mile round trip to refill with water greatly reduced the amount of water delivered to the fire, compared to how much could have been dropped if a closer water source had been created or used.

Normally aviation resources do not put out a fire, but they can sometimes slow down the spread until ground resources can move in to construct direct fireline around the perimeter, removing the vegetation, or fuel, and preventing it from growing. But if firefighters are not allowed to directly access the fire’s edge due to a perceived safety issue, very large amounts of water or fire retardant can be applied from the air that in some cases can virtually put out a small fire. Or, pause the spread until rains arrive — like it did late in the day on November 28.

Another alternative to directly attacking a fire is to construct firelines some distance away, or use natural barriers, and intentionally burn out the vegetation between that line and the fire, stopping the spread. This was not done during the five days before the fire burned into Gatlinburg as the fire grew from 5 to 35 acres during that period.

Wind speeds

Strong winds can not only cause a fire to grow quickly, but they can also make the use of air tankers and helicopters impossible. Any retardant or water dropped can be blown far off target, making it ineffective. And, strong gusty winds can make it unsafe for aircraft flying low and slow over rough terrain.

There were times between November 23 and 28 when the wind speeds were too high to allow the use of aircraft.

Wind speeds at Cades Cove and Cove Mountain
Wind speeds at Cades Cove and Cove Mountain, November 23-29, 2016. .
The data in the charts above, supplied by Great Smoky Mountains National Park, was recorded at Cades Cove 20 miles west of the fire, and Cove Mountain 8 miles northwest of the fire. It shows that the winds would have allowed the safe and effective use of aircraft during the daylight hours from early afternoon on November 24 through sundown on November 27. But they were not used except for the helicopters during the afternoon of November 27. The wind was far too strong on November 28 and 29 for aircraft.

Energy Release Component (ERC)

The ERC is calculated daily at Fire Weather Stations around the United States. It is a number related to the available energy (BTU) per unit area (square foot) within the flaming front at the head of a vegetation fire. Daily variations in ERC are due to changes in moisture content of the various fuels present, both live and dead.

Energy Release Component, Tennessee mountains
Energy Release Component, Tennessee mountains.
The average ERC for the Tennessee mountains in late November is 16 to 20. The 97th percentile is 40, meaning 97 percent of the time it is lower than that number. Since early September it had mostly been above the 90th percentile and was above the 97th percentile during much of November. The day the fire started the ERC was 41, and in the following days was higher, reaching 50 at one point which was the highest ever recorded on that date in the 23-year history of data from that weather station.

When the ERC is above average, and especially when it is higher than the 90th or 97th percentile, fires spread more quickly, burn deeper into the duff and organic material on the forest floor, and exhibit more resistance to control.

The ERC, along with other indicators, is often used as a planning tool to preposition firefighting resources, increasing their numbers in areas where large fires are expected. Days off for firefighters can be cancelled and prescribed fires postponed.

On December 5 we wrote about the Keetch-Byram Drought Index (KBDI), an indicator of drought and its effect on how wildfires burn. On November 23 when the fire was discovered the KBDI was very high, 599, Molly Schroer, a spokesperson for the fire’s Incident Management Team told us. For reference, 600 or above would indicate severe drought and increased wildfire occurrence. Intense, deep burning fires with significant downwind spotting should be expected under those conditions.

Many fire managers, when informed about a new fire under those KBDI and ERC conditions, would have attacked it immediately and aggressively with overwhelming force, from both the air and the ground.

For the most current information about the Chimney Tops 2 Fire at Gatlinburg, see our articles tagged “Chimney 2 Fire”.

Typos or errors, report them HERE.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire. Google+

14 thoughts on “Analysis of wind, vegetation, and air tankers before the fire burned into Gatlinburg”

  1. Here is the weather forecasting audio that the scanner traffic. Audio has given by firefighter dispatch at 8:45 am on November 28th, 2016

    However, I think the real question is, we know that weather did play a huge part, but did an arsonist or arsonists, play an even greater role?
    Listen to the youtube video that I posted online between that occurred between 11 and 11:30 am.

    If anyone can clear up or give me advice on how to clear up where the arson occurred, that 202 was operating that would be great! It can really call into question the “spot fire” as a natural incident.

    A spot fire was discovered in the Twin Creeks area of the park, 3 miles downwind from Bullhead Ridge, at about 11:30 a.m. The Fire was about 1.5 miles from the park boundary.  Gatlinburg Fire Department and park crews responded to provide structure protection. TN Division of Forestry responded with bulldozers and crews.

    Here is one more link. If anyone can figure out where this event took place…please post!

  2. Look at all those air tankers just sitting around. During the South Canyon Fire in Colorado it was the same scenario. Close proximity air tankers on the ground assigned to something? The Chimney Fire 2 reminds me of the disastrous Oakland Hills (Tunnel)fire which still holds the record for everything lost, property, lives. The comparison is Thanksgiving and the World Series. On the flip side, the Witch Fire in Southern California which cleaned out a swath of lives and structures pushed by strong Santa Ana winds didn’t allow fire fighters a fighting chance in the first few minutes. I have a suggestion; maybe one of the lead plane pilots at Chattanooga could have been asked to go take a look at the fires, even on Thanksgiving, and make a recommendation. Forgot, no retardant in the Park. These tankers can even care potable clear water, I think. Pretty unique thinking.

  3. Johnny, here is a paste (in “quotations”) from an old 1996 GSMNP fire manual. I’ll look to see if they have an updated manual regarding retardants, etc. According to this old manual, they can use retardants as long as it is 200 yards away from a stream, etc. So, being the initial fire was at the Chimney’s summit, NPS apparently could have used retardants for suppression.

    “a. Minimize use of retardant. The Park’s aquatic ecosystem requires
    protection for various reasons. The higher elevations support
    populations of the native brook trout. The streams at the lower
    elevations support a very diverse fish population with state-listed
    species, plus some of the most diverse aquatic insect populations in the
    nation. The Park is known for its quality fishing and serves as an
    ecological model for the region. As a result, it will be standard
    practice to keep chemical retardant at least 200 yards from any stream or

    Because of unique characteristics or special uses, there are a few
    streams or areas in the Park that require more than the 200 yard-wide
    buffer zone.”

    1. Although retardant is a good temporary line product it’s not the answer for all fires. Deep seated sub terrain fires; class A foam like the Super Scoopers guys use. Gels provide fuel cooling, like foam lowers ignition temperature to slow combustion (smoldering) and retain surface wetting for a short period of time which can act like retardant. Application of water or water enhanced products are measure when released from an air tanker as a value of gallons in 100 square feet. 2 gallons per 100 sq. for lighter fuels, grass and sparse brush and over 12 gallons per 100 sq.; what ever it cascades on will be out or smolder for days. Air tankers adjust their delivery to meet the amount of water (chemical) needed to accomplish the task. To put this into perspective a C 130 or RJ 85 delivering water to the initial stage of the Chimney 2 Fire (Thanksgiving) selecting coverage level 8 (gal/100sq) would equate to about > 1/4 inch of rain fall per drop. The rotary wing folks set their own coverage levels by airspeed. Light rain to a dam bursting. Some times you have to beat Mother Nature at her own game.

      1. Thanks Johnny for the insight and for mentioning that it could have been done early on like Thanksgiving. Tommy

  4. Bill posts the most relevant information long before the new organizations (primarily Knox News, which actually did post a very good progressive timeline of the Chimney Tops fire last week

    Yes, there was so much that could have been done in the first few days of the fire (per my previous posts), but ultimately it comes down to lack of or no training for wind driven wildfires for all those in charge of the situation: GSMNP, TEMA, Forestry Commission, country and town fire departments.

    Interesting to read the Knox News timeline – calls for fire fighting help went out for early the afternoon of Nov. 28, yet no pre-evacuation notice was sent out. When Twin Creeks fire quickly spread from winds, evacuation notice was given to homes in that area. Yet still no fire warnings were given to the greater Gatlinburg community. In fact, it was documented that local officials were telling concerned local citizens that things were under control as late as 5:00 PM. Totally irresponsible. Only the local private school had the common sense to close early due to heavy smoke.

    As someone pointed out in prior posts, basically all of the Incident Management Teams were assigned to other big fires (20,000+ acres) around the southeast. The Chimney Tops fire was too small qualify the week of Thanksgiving. However, on the following Sunday, the weather forecast for 40 mph winds was enough to get GSMNP to call for an IMT. As it takes time to move people and equipment, even at that point it would be Tuesday before any of those teams could be there.

    Despite lack of adequate training of those who could have changed the progression of the fire, chances are the GSMNP didn’t pursue equipment available for fire fighting to the extent that they knew the air tankers were available (or they didn’t want to take responsibility for running up the expense of requesting the planes available). Yet certainly, TN Forestry and National Forests managers knew those tankers were nearby (speculating those were the planes used on Joyce Kilmer and Cohutta fires-don’t know how to track that).

    As to why the helicopters (were they TN National Guard choppers from NG unit at Knox airport?) did water pickups from Fontana Lake on the other side of 6,000+ ft. mountains instead of the closer and downhill Douglas Lake, I can only speculate. Flying to Fontana Lake from Chimney Tops was flying over nothing but forests. Going to Douglas Lake meant flying over densely populated areas. Noise complaints took priority over knocking down a fire before predicted high winds developed?

    The TN governor said he was going to form a committee to investigate the whole Chimney Tops situation and how it was handled. I wonder when that will happen, but there is no word at this point. Yet relevant information keeps popping up from a number of sources. Let’s hope the investigation team makes use of all of them.

  5. Two of Neptunes 146 tankers were based at Tri-Cities airport with a portable tanker base 70 miles from Gatlinburg with two CL-415 waterscoopers and an ASM. Scoopers had been there for about 2 weeks and had an order to go to the fire Monday morning (Nov. 28th) about 11 am. Order canceled due to concerns about wind. By Monday it was probably too late to do much by air…. (…fire started 5 days earlier…IA, IA, IA! ?)

  6. See the link here on WBIR’s News Video on “A Year in the Great Smoky Mountains National Park.” 2:04 minutes into the segment is either a classic case of denial and ignorance; or good ole CYA – cover up and get the heat off my back. The potential for a devastating wildfire impacting nearby communities is in their fire manual – not to mention a University of Tennessee wildfire expert warning them of pending wildfires. Surely local media isn’t going to investigate this firefighter’s opinion. Thank God for all the real firefighters commenting here and Bill for his work with Wildfire Today.


  7. So with wind and weather being such a huge factor, you would think that fire crews would be equipped with some wind technology like or similar items. Small light weight easy to use.

    However, listen to this audio. During the crucial hours leading up to the perfect storm. You can hear that the firefighter is just guessing!

    Clearly, I would think that they would have a weather device. Remember this audio highlighting that they have no phone service so they could not get a weather forecast.

    1. Virtually all 20-person hand crews have various forms of wind meters. But there may not have been any 20-person hand crews on the fire when it burned into Gatlinburg. And of course field observers have wind meters, but there may not have been any of those either. Many engine crews also have weather kits.

  8. Bad fire produced by high winds, people killed and structures destroyed. Got to find someone to blame, don’t we? Are all those western fires which caused damage some official’s fault too?

  9. First off, I want to thank all the firefighters from around the state, region, and country that came to help save our town. Like most everybody in Sevier County, I spent all night Monday 11/28 desperately praying everyone was able to make it off the mountains and that the whole town would not burn down as it was clear the city was very quickly surrounded by fire. It’s very literally plain to see the heroic and epic fight that was waged to save my hometown.

    And, thank you, Bill, for bringing relevant facts to light regarding GSMNP letting the fire burn and spread from Wednesday until Sunday before doing any water drops. My cousin who had fought fires out west in his younger days had come over Friday 11/25 upset and worried the park appeared to be applying a “let it burn” approach to the Chimney fire. The drought conditions were extreme and there was an unnatural and monumental buildup of deadwood due to the invasive species kill off of hemlock, pine, and ash laying all over the forest floor right up to the city limits. The park would not allow clearing of any deadwood even right up to the city limits. I hope this policy is reviewed along with every factor and decision that resulted in this fire being allowed to fester and burn until it jumped park boundaries, took so much life and property, and nearly destroying our whole town. This can never ever be allowed to happen anywhere ever again. Thank you from the bottom of my heart for shining a bright light during this very dark time.

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