(Reuters) – A stubborn Colorado wildfire grew by around a fifth on Saturday, consuming sparsely populated land as low humidity and high winds left firefighters bracing for it to spread, officials said.
“Weather will be a concern this weekend as critical fire weather conditions are expected,” fire officials said in a Saturday email update on the so-called 416 Fire. “Southwest to west winds will be strengthening across southwest Colorado this weekend.”
The Haines Index, used by firefighters to assess the stability and dryness of air over fires, is at its maximum level of six, officials said.
“This indicates that there is a high potential for extreme fire behavior, intensity, and growth,” they added.
As of Saturday morning, the Colorado fire remained at 10 percent contained, but it had grown by about 1,500 acres (607 hectares) since Friday, mostly in less inhabited areas to the west that officials said they were monitoring while they concentrate on protecting structures to the east, north and south.
Officials said they ramped up their response to the fire, which had scorched 8,691 acres, up from 7,180 the day before, to a maximum Type 1 from Type 2, implying additional resources to battle the blaze.
In 2017, a near-record 10 million acres (4 million hectares) were burned in U.S. wildfires, the National Interagency Coordination Center said. The same agency issued a June forecast for “above-normal significant large fire potential” this month in Southern California and the Four Corners region of Colorado, New Mexico, Arizona and Utah, because of a deepening drought and ample fuel for wildfires.
Firefighters have kept the Colorado fire to the west of Highway 550 and away from structures, county commissioners in La Plata County, Colorado, said in a Saturday Facebook post. Fire officials said in the Saturday update that Highway 550 was closed from mile marker 32 to 47 and pilot cars were escorting traffic through there.
A new blaze about 13 miles to the west, known as the Burro fire, prompted U.S. Forest Service officials on Saturday to close part of the Colorado trail in the San Juan National Forest.
Reporting by Peter Szekely, Editing by Rosalba O’Brien