4 days ago
What's driving the explosive fires in the West?
Wildfires are growing explosively in the Western U.S. amid hot, dry and windy conditions, chewing through thousands of acres and putting up ominous smoke columns.
In western Colorado, the Lee Fire was has consumed at least 45,000 acres as of late Wednesday, burning with 'extreme fire behavior' and threatening the nearby town of Meeker. The Gifford Fire in central California ballooned to California's largest this year at more than 91,000 acres, after igniting on Aug. 1. And the Dragon Bravo Fire, which has been marching through northern Arizona for more than a month, is now over 130,000 acres.
'The fire behavior we've seen on some of these fires this year has been surprising,' said Steven Larrabee, a fuels and fire analyst for the National Interagency Coordination Center. 'That does tell us an awful lot about the condition of the fuels and the weather impacts on those.'
The blazes are intensifying as several states bake under a heat dome, and while strong winds sweep through the interior West. But even before this week's heat and wind, the stage was set for major fires. For months, outlooks have predicted there would be high fire risk for vast swaths of the West this summer and into fall due to a combination of deepening drought, early snowmelt, high temperatures and thick vegetation left behind from previous wet seasons.
As of Wednesday, 38 large fires were burning across nine western states, according to the National Interagency Fire Center, which raised its risk level to a 4 out of 5 this week, citing a heavy resource commitment and weather that will continue fuel the flames.
Fire risk has been particularly high in the interior West, where winds have been whipping all week.
The winds will be widespread again on Thursday and Friday, with gusts up to 50 mph bringing 'critical fire weather' from Nevada to Colorado and Wyoming, according to the Storm Prediction Center. This area is stuck between strong high pressure over the Southwest and trough of low pressure over the Pacific Northwest, driving persistent winds.
'If the wind is blowing 30 or 40 mph you can have rapid rates of spread for several miles very quickly,' said Basil Newmerzhycky, lead meteorologist at the Great Basin Coordination Center in Salt Lake City.
The region is primed for wildfire because of a dry winter, rapid snowmelt this spring and the absence of midsummer monsoon rains, along with above-normal temperatures over the last several months.
'More than half our stations are near or at record dry levels,' Newmerzhycky said.
Typically, monsoon rains would reach the I-80 corridor, calming the fire season in the southern two-thirds of Nevada and Utah and in much of Colorado, he said. But moisture with storms has been fleeting this far north.
'The Intermountain West has really just stayed in the oven with repeated daily lightning events,' Larrabee of the National Interagency Coordination Center said.
Northern Arizona, where the Dragon Bravo Fire has been burning since it ignited on July 4, is also waiting for monsoon rain.
'That fire is burning unusually aggressively, in my opinion,' said Larrabee. In mid-July, the blaze destroyed numerous structures on the north rim of the Grand Canyon and is now burning on the Kaibab Plateau, an area of relatively flat terrain.
'It's not a place that typically has three weeks of sustained daily fire growth — that's unusual,' he said.
That's in part a testament to how dry the vegetation is, he said.
Across much of the West, mountains and forests are more prone to intense wildfires this year because of snow drought and a rapid melt-off during spring heat waves. Snow conditions in Arizona were especially severe — the state saw its driest December-January period on record, according to the Arizona State Climate Office. It also saw its second-warmest July-to-June period on record (July 2024 through June 2025).
'We're looking at not just what is happening right now but what happened a year ago with temperature and precipitation,' said Erinanne Saffell, Arizona's state climatologist. In addition to the exceptionally dry winter, last summer and fall were fairly dry as well, she said.
The Gifford Fire is burning in San Luis Obispo and Santa Barbara Counties — in an area of the Los Padres National Forest with inaccessible, steep terrain, thick grasses and highly flammable native shrub vegetation — with plenty of area to burn.
On Aug. 1, the blaze ignited along a highway in grass and then moved into canyons and slopes with dense vegetation, releasing towering plumes of smoke, according to Scott Safechuck, public information officer for the Santa Barbara County Fire Department.
'When it gets into that heavier chaparral and it's moving up a slope, it can create a lot of energy,' he said.
The blaze is now over 91,000 acres — the state's largest so far this year — and 9 percent contained as of late Wednesday. Vegetation in the area is 'critically dry,' easily ignited by embers and carrying fire well, Safechuck said.
Much of central and Southern California is in moderate to extreme drought, and inland areas have been warmer than normal this summer, although cool weather has persisted along the coast.
Although fire activity has calmed some, hot weather on Thursday may re-intensify the fire, possibly threatening nearby rural communities that are under evacuation orders.
'If we start getting plume-dominated fire again, it can cause erratic fire behavior and start consuming vegetation at a rapid rate,' Safechuck said.
