What caused the wildfire in Colorado?

Denver is likely to receive snowfall on Friday, which meteorologist hope will bring down blaze

Extreme dryness and lack of precipitation have been pegged as the reasons behind the spread of a devastating wildfire that tore through multiple towns in Boulder, Colorado, forcing thousands of people, including hospital patients, to evacuate on Thursday.

Small fires cropped up on the grass in a median or in a dumpster in the middle of a parking lot, which then spread at a rapid speed due to gusting winds. The wind, as powerful as 110mph, knocked over power lines, pushing the fire across neighbourhoods, burning down more than 1,600 acres.

More than 30,000 people in Superior and Louisville towns in Colorado were ordered to evacuate their homes. Some sections of the road on the US-36 highway were closed.

While wildfires are relatively less common during December in Colorado, record dryness led to the eruption of Thursday’s devastating fire, Denver’s National Weather Service said.

“For all periods from Jul 1st to Dec 29th (essentially the second half of the year), Denver has been the driest on record by over an inch. Snowfall is at record low levels, too,” the agency tweeted.

Although Denver received a generous amount of rainfall from February to June, it has flat-lined since then, the weather service noted.

After setting a record for most days without snow, Denver got a small storm on 10 December. However, since then, it hasn't snowed. Snowfall was expected in the region on Friday, which meteorologists believe will help bring down the fire.

At least 90 per cent of Boulder County is reportedly in severe or extreme drought and hasn’t seen substantial rainfall since mid-summer.

“With any snow on the ground, this absolutely would not have happened in the way that it did,” snow hydrologist Keith Musselman told the Associated Press.

Daniel Swain, a meteorologist at the University of California, tweeted that it was “genuinely hard to believe” these fires were happening in December.

“But take a record warm and dry fall, only 1 inch of snow so far this season, & add an extreme (100mph) downslope windstorm...and extremely fast-moving/dangerous fires are the result".

Colorado governor Jared Polis declared a state of emergency on Thursday afternoon, which allowed the state to deploy emergency funds and resources including the Colorado National Guard.

Six people were treated for injuries from the wildfires at the UCHealth hospital in the neighbouring city of Broomfield, spokesperson Kelli Christensen said.

Early estimates suggested approximately 370 homes in the Sagamore subdivision were lost, Boulder County Sheriff Joe Pelle said. He added that about 210 homes were lost in Old Town Superior.