Above: The Drought Monitor issued November 29 showed “Exceptional Drought”, the highest category, for the Gatlinburg area and large sections of Tennessee, Georgia, Alabama, North Carolina, and South Carolina.
On Monday, December 5, the Incident Management Team (IMT) on the Chimney Tops 2 Fire that burned from Great Smoky Mountains National Park (GRSM) into the Gatlinburg area reported that it has caused the deaths of 14 people. Over 130 sustained injuries, and 1,684 structures have been damaged or destroyed. Approximately 14,000 residents were originally forced to evacuate.
There are three broad categories of conditions that affect the way a wildfire burns: weather, fuels (vegetation), and topography. When the Chimney Tops 2 Fire burned into Gatlinburg on November 28, 2016 and destroyed those structures it was driven primarily by weather — specifically, very strong winds.
But the condition of the fuel was also important since it happened during what the National Weather Service (NWS) calls “exceptional drought” conditions. Much of the southeastern United States had been suffering extremely dry conditions for two to three months.
One indicator of drought and its effect on how wildfires burn is the Keetch-Byram Drought Index (KBDI). (The fire was in eastern Tennessee near the North Carolina border.)
On November 23 when the fire was discovered the KBDI was 599, Molly Schroer, a spokesperson for the IMT 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. A fire burning under those conditions would likely burn more intensely, have a rate of spread faster than normal, and have more resistance to control. Many fire managers in that situation would immediately attack emerging fires very aggressively with overwhelming force, that is, many firefighters on the ground assisted by numerous aircraft dropping water or fire retardant.
Ms. Schroer said she was not aware of any actual on-the-ground fire suppression efforts, other than perhaps some work on a distant indirect fireline, until Monday November 28, after the fire had grown large and crossed US Highway 141, the main road into the park. That is when it began moving rapidly toward Gatlinburg. Firefighting aircraft were not used until helicopters dropped water on the fire Sunday afternoon, November 27 four days after it started.
Wednesday, November 23, the day the fire started
At about 5:20 p.m. the fire was discovered near the top of a steep hill called Chimney Tops not far from where another fire occurred about a week before. GRSM firefighters spotted the new fire as they returned from responding to a report of a vehicle fire. The earlier fire on the hill was named “Chimney Tops” — hence the name “Chimney Tops 2” for the new blaze.
According to Ms. Schroer, firefighters walked up the Chimney Tops Trail to the top of the hill to size it up. But very little if any fire suppression activity occurred until Monday, November 28. The action taken by firefighters on Monday was defensive, to protect threatened structures at a nearby National Park Service picnic ground.
Investigators have determined that the fire was human-caused and are asking for information from anyone who has information about people or vehicles that were seen in the area that day. The Tip Line is 888-653-0009.
Narrowing it down to human-causes is easy for an investigator. It means they eliminated natural causes, such as lightning and volcano eruptions. The fire could have been accidental, or it may have been intentional.
Continue reading “Analyzing the fire that burned into Gatlinburg”
