Wildfires raging in the Tennessee resort towns of Gatlinburg and Pigeon Forge, north of the Great Smoky Mountains, have forced residents and visitors to evacuate. (Reuters)

The hottest and driest autumn on record is fueling what the mayor of Gatlinburg, Tenn., is calling “a fire for the history books.” Hundreds of structures have been burned to the ground, 14,000 residents were forced to flee for their lives, and though there were no reports of fatalities on Tuesday morning, at least four people are being treated for burns, three of which were classified as “severe.”

The fires sprung up so fast and spread so quickly that officials hadn’t been able to figure out how much ground the blazes actually covered on Tuesday morning.

How did this happen? In the immediate — strong winds, downed trees and live power lines sparking across dry autumn leaves. In the long-term — few tropical storms, months of drought and cold fronts that time and time again brought more wind than rain. Wildfires have been charring the landscape in the Great Smoky Mountains for months, and it was only a matter of time before they reached a community like Gatlinburg.

On Sunday night, a high wind watch was issued for eastern Tennessee ahead of a strong cold front. The National Weather Service was forecasting sustained winds at 20 to 40 mph, with gusts over 60 mph in higher elevations:

(National Weather Service, Morristown, Tenn.)

Weather stations are sparse in Great Smoky Mountains, but the Weather Service received a 56-mph wind gust report at Sevierville, Tenn., about 10 miles north of Gatlinburg on Monday night. At a news conference, the Gatlinburg fire chief cited an 87-mph wind gust, but the Capital Weather Gang has not been able to confirm that report. The Weather Service noted that 80-mph gusts were certainly possible on the mountain peaks.

At one personal weather station on the east side of Gatlinburg, gusts spiked at 69 mph and the temperature shot up to 119 degrees at 8:34 p.m. before the station went offline, presumably engulfed in flames.

“Wind gusts carried burning embers long distances causing new spot fires to ignite across the north-central area of the park and into Gatlinburg,” Great Smoky Mountains National Park wrote on its Facebook page Tuesday morning. “In addition, high winds caused numerous trees to fall throughout the evening on Monday bringing down power lines across the area that ignited additional new fires that spread rapidly due to sustained winds of over 40 mph.”

Power went out for thousands of customers in Sevier County, where Gatlinburg is located, after winds knocked down trees and power lines. Live wires are at least part of the reason the Chimney Top Fire spread so rapidly overnight.

“The wind is not helping, and the rain is not here yet,” Gatlinburg Fire Department Chief Greg Miller said in a news conference on Monday night. “These are the worst possible conditions imaginable.”

Of course, high winds and downed power lines don’t usually spark such devastating wildfires. The key ingredient in eastern Tennessee is the ongoing, severe drought. All of Sevier County is in an “exceptional drought,” which is the worst on the U.S. Drought Monitor Scale. It means there are widespread crop and pasture losses, shortages in water reservoirs, streams and wells.

In short, eastern Tennessee has turned into a tinderbox.

This fall has been the hottest and driest in the city’s history, reports Weather Underground’s Bob Henson. In a normal year, Gatlinburg averages 56 inches of rain, “so it doesn’t take much time for a drought to hit this normally moist landscape hard,” Henson wrote.

Henson also noted that in the distant past, natural, less-intense wildfires occurred in this region every few years, which actually prevents large, destructive fires like this from happening. But fire suppression began in the early 20th century, putting an end to the natural cycle, and increasing the likelihood of massive fires.

Between the drought and the fire suppression, “it’s a recipe for disaster,” Henson added.

Even though multiple cold fronts are passing through the Southeast this week, the rain that they generate will not be enough to help firefighters. As of Tuesday afternoon, only ½-inch of rain had fallen in nearby Knoxville, Tenn. Another ½ to 1 inch is possible through Thursday morning.