A dire wildfire crisis is unfolding in Colorado after a blaze exploded sixfold in size in just 24 hours, growing to about 170,000 acres on Thursday evening. The East Troublesome Fire, burning in Grand County and extending now into Rocky Mountain National Park, forced hundreds to quickly evacuate from Grand Lake and Granby overnight, with more evacuations taking place Thursday and an unknown number of structures reportedly destroyed.

The blaze has all the hallmarks of climate change. It’s burning at an elevation of 9,000 feet at a time of year when snow should be falling. The fire is also raging during a severe drought, aggravated by record heat, through stands of trees killed or weakened by a bark beetle infestation.

The East Troublesome Fire is now the second-largest wildfire in Colorado history. Three of the state’s five largest wildfires on record have now occurred in 2020. The largest, the Cameron Peak Fire, is still burning just west of Fort Collins.

Noel Livingston, who leads the team of firefighters tackling this blaze as incident commander for Pacific Northwest Team Three, said that crews saw an “amazing amount of fire spread yesterday.” In an afternoon press briefing Thursday, Livingston said the 100,000 acres of fire growth that occurred late Wednesday and into Thursday morning is “Really unheard of for a fire in this part of the world in timber."

At times, National Weather Service Doppler radar showed the smoke plume from the blaze towering almost 40,000 feet above the surface, a sign of extreme fire behavior. Typically, at such a high elevation in the state, the weather at this time of year would not result in such a high wildfire danger. Instead, a red flag warning for “critical” fire weather risk is in effect through 7 p.m. local time Thursday, with winds forecast to gust up to 50 mph, making efforts to increase fire containment difficult.

“We saw about 20 miles of fire growth throughout the day and throughout the night, which equated to about 100,000 acres of additional fire activity,” Livingston said.

Livingston said the fire burned quickly through heavily forested areas north of Granby and Grand Lake. A pre-evacuation notice was issued for Granby on Thursday.

The fire jumped the continental divide in Rocky Mountain National Park, despite being areas that are above the tree line. That is an extremely rare occurrence and puts new downwind areas to the east, such as Estes Park, at risk. A merging of this fire with the Cameron Peak Fire is even possible, Livingston said during a news conference Thursday morning.

Evacuation orders for the national park and parts of Estes Park were issued, with traffic backups reported Thursday afternoon for people leaving Estes Park. On Thursday afternoon, the sky in Estes Park had turned dark as night, contrasted against the lights from cars backing up on local roads out of town.

The East Troublesome Fire, now the fourth-largest wildfire in Colorado history as of Oct. 22, has forced hundreds to evacuate across Grand County, Colo. (The Washington Post)

The ingredients for the massive, rapid growth of this fire, Livingston said, were the thick stands of trees, many of which had been weakened or killed by beetle invasions in recent years, a phenomena linked to climate change that is occurring across vast stretches of the West and into Canada.

As temperatures have increased in Colorado, it has given once-scarce pests, including mountain bark beetles, that were held in check by extremely cold winter temperatures, an opportunity to spread and damage or destroy trees. Studies have shown that in some ecosystems, these dead or weakened trees can accelerate blazes, while in others they may actually slow down some wildfires.

Livingston also pointed to extremely dry conditions and strong winds that pushed the fire through the timbered areas. Winds near the fire were gusting to 60 mph at times on Wednesday.

Winds are predicted to remain strong for the next two days, said Nick Nauslar, a predictive-services meteorologist with the National Interagency Fire Center in Boise, Idaho. He noted in an interview that at 9 p.m. on Wednesday night, near the fire at 8,500 feet in elevation, the air temperature was 70 degrees and winds were gusting to 68 mph.

“That’s pretty rare just in the summer for 8,500 feet, let alone late October,” Nauslar said, since normally it would be colder at that height. “I’ve used the word ‘unprecedented’ before and I’m starting to run out of adjectives to describe what’s happening this fire season," he said.

Grand County Sheriff Brett Schroetlin published a Facebook video around 1 a.m. Thursday explaining how tough the night had been.

“I have a message,” he said. “I’m not even sure what those words are. Today [Wednesday] has been an extremely, extremely challenging day for our community. We knew this fire was here. We knew the impacts of it. We looked at every possible potential for this fire. We never, ever expected 6,000 acres per hour to come upon our community."

The winds were strong and, as a result, the fire’s behavior was as well.

“As we drive around this northern part of Grand County, I don’t know what we’ll see in the morning, to be honest,” he said. “But you know what? Together, as a community, we’re going to get through this.”

The forecast for Thursday calls for more high winds and low relative humidity in the region of the fire.

“Unfortunately, today is another fire day,” Livingston said. “We have forecasted high winds coming in this afternoon with a cold front[al] passage. We have again forecasted dry conditions. And we obviously have a lot of available fuel this fire could continue to spread in.

“We anticipate another day of large fire growth,” Livingston said.

The state Colorado is suffering drought conditions for the first time since 2013. Human-caused climate change is sparking more frequent and intense wildfires in much of the West, along with an extension of the wildfire season, studies show. Higher air temperatures are worsening droughts, as well.

California is also experiencing a record wildfire season. More than 4.1 million acres have burned, and more than 9,200 homes and other structures destroyed since Jan. 1. California wildfires have killed 31 people so far this year, with more high winds in the forecast for the next week, which could spread any new blazes that ignite.