By Marcy Stamper
Veterans of massive fires around the country used superlatives to describe the sinister power and rapid growth of the Carlton Complex Fire.
“In 17 years, I’ve never seen a fire like this,” said Ben Curtis, a fire behavior analyst with the Incident Management Team on Thursday (July 17). The fire grew from 65 acres on Wednesday afternoon to 25,000 acres in just 24 hours, said Curtis.
What started as four fires sparked by lightning on Monday, July 14, had combined within days to form the largest fire in Washington-state history. At both Cougar Flat near Pearrygin Lake and Gold Creek, there were small blazes among a few trees and shrubs when the fire was first detected last Monday. That afternoon firefighters were already concentrating on Texas Creek, where half a dozen homes were at risk from a blaze that had sent a huge plume above parched hillsides in 100-degree heat and strong winds.
Bill Moody said that a fire of this size and intensity close to town is the most critical situation he has witnessed in his 57 years as a smokejumper and as an air attack specialist on fires locally and around the country.
“Last year, I thought I’d been to the biggest fire ever—the Rim Fire in Yosemite—but this one is bigger,” said Bob Ramirez, a fire information officer who arrived in the valley on Saturday. While the Rim Fire had been very damaging to the environment and wildlife, it did not directly affect communities, he said.
Once the Carlton Complex Fire started, extreme conditions caused the fire to spread with alarming force and speed. Two weeks of temperatures in the upper 90s and low 100s, extremely low humidity, a low snow pack that melted quickly, virtually nonexistent spring rains, and unusually strong wind gusts meant that there was a 100-percent chance that any spark or ember that landed on the ground would ignite a new fire, said Curtis.
In the early days of the fire, the Methow Valley did not even get the typical night-time rise in humidity that can help fuels recover, meaning that firefighters did not have an early-morning window when they could make a safe, productive attack on the fire, said Curtis.
With strong winds and unstable atmospheric conditions, the fire sent plumes more than 25,000 feet into the air. Once a plume gets tall enough to meet cooler air, it collapses, but it then sucks more wind into itself and builds still more heat and intensity. “It’s a perpetuating cycle,” said Curtis.
What fire analysts call “plume-dominated fire behavior” means a fire can spread in any direction, because the fire will pull burning debris into the column and spit it out anywhere, said Curtis. Embers can travel as far as a mile from the plume.
The frightening plumes that look like mushroom clouds form when the fire builds intensity. The hotter it gets, the higher the plume goes, since warm air is lighter.
Although the plume can appear white and fluffy, it consists largely of smoke, which contains a high percentage of moisture from evergreen needles, branches and unburned byproducts, said Curtis.
As a fire gets bigger, it can generate its own weather and even modify the local weather or create a thundercloud and lightning, sparking even more fires on the perimeter, said Moody. Once large areas have been blackened by flames, solar radiation will create additional heat, he said.
Fighting a fire
National crews descended on the Carlton Complex with thousands of firefighters, helicopters and planes dropping retardant, but that onslaught was no match for the extreme conditions. “We need a change in the weather to be able to stop this fire,” said Curtis on the fire’s fourth day.
Fingers of the fire raced in numerous directions from its start in the Methow Valley. Strong winds propelled the fire at incredible speed, pushing it across Highway 153 south of Carlton and over hills covered with dry grasses and shrubs to engulf Pateros with little warning. After that, one leg of the fire headed toward Chelan, while another flank went north from Pateros toward Brewster and Malott and on to the east slope of the Loup summit.
For many days conditions were so extreme, with flames up to 30 feet long, that all firefighters could do was protect structures and monitor and extinguish any spot fires. “It’s a safety issue, and it’s not effective,” said Curtis. Retardant was helping slightly, but the fire was creating new spot fires beyond the retardant lines, said Curtis.
Water and retardant drops are used in large part to cool the fire so that firefighters can safely work building a line near the fire. Retardant coats vegetation and helps it resist ignition after it dries, said Moody.
Firefighters aim for a complete containment line around the entire perimeter of a fire, starting at the heel (the origin point) and working continuously along both flanks. The leading edge is the most intense part of a fire, and it also presents the greatest risks to firefighters.
Depending on the terrain, firefighters use hand tools or a bulldozer to dig a containment line, clearing vegetation down to mineral soil as close to the edge of a fire as possible. The job has to be done carefully, because the fire will escape through any break in the line, said Moody.
With flames under four feet long, firefighters can mount a direct attack, digging a line along the exact perimeter of the fire. With longer flames, crews work parallel, anywhere from 10 to 200 feet from the edge, said Moody.
When the fire is burning too intensely to allow crews to build a close fire line, they will work hundreds of feet—or even miles—from the active fire to take advantage of natural barriers such as a road, river or rocks, said Moody. Then they burn the space in between to create a buffer between the active fire and the barrier.
Intense fires also pose safety problems for aircraft, which can be affected by strong winds and poor visibility, said Moody.
Even natural barriers can prove no match for the most severe fires, particularly in windy conditions, said Moody. The fire can join with spot fires some distance from the main fire and leapfrog, igniting even more areas.