The BC Wildfire Service (BCWS) says an “incredibly rare phenomenon” known as a fire whirl was caught on camera over Gun Lake, adjacent to an out-of-control blaze in British Columbia’s Interior.
The whirl, or fire tornado, was seen spinning through the Interior on Aug. 17, when overnight ground personnel were responding to the Downton Lake wildfire on the Bendor Range Complex, near Lillooet, according to the BCWS.
That’s when a cold front passed through the area between 3 a.m. and 6 a.m., it says, with video footage showing the combination of high fire intensity, strong winds and air mass instability.
“These fire whirls are vertically oriented, intensely rotating columns of gas and flame,” the BCWS said in a social media post. “The complex terrain, downslope winds and impact of the passing cold front provided the necessary conditions for the formation of this fire whirl over Gun Lake.”
It says strong winds from the southwest, a reduced dew point of -11 C and a relative humidity value of 14 per cent, “incredibly rare to see overnight,” played in favour of the whirl’s growth.
On the social media platform X, formerly known as Twitter, the video captured by fire crews has been shared hundreds of times:
Last week, a cold front passed through the province following several days of hot, dry weather. pic.twitter.com/fHbPsizjbr
— BC Wildfire Service (@BCGovFireInfo) August 22, 2023
The BCWS notes, however, that these conditions are unique and extreme and seldom experienced in B.C.
“With this combination of conditions and fire behaviour, fire intensity was more extreme during this overnight period, reaching intensities that hadn’t been seen even during the day,” it added.
As of Tuesday morning on the BCWS dashboard, the Downton Lake wildfire measured more than 7,400 hectares in size. The fire, which is highly visible, is believed to be lightning caused.
The Squamish-Lillooet Regional District on Monday said the fire was continuing to grow and destroy structures in the area, with an evacuation alert in effect for local residents.