Normally smoke from a wildfire isn’t anyone’s friend, but the BC Wildfire Service says smoke gathering in the Lower Similkameen Valley has helped firefighters keep the Snowy Mountain fire away from populated areas.
“(The fire is) certainly active in the alpine areas, but we do have a fairly intensive inversion over the fire in the mid-slope to valley-bottom areas,” explained Claire Allen, a Fire Information Officer with the BC Wildfire Service yesterday.
“That does serve to make it a bit more humid so we’re seeing less fire behaviour occurring in the lower portions of the fire.”
Instead the blaze, now estimated at more than 12,000 hectares, has been pushed at higher altitudes south toward the US border.
Monday, the fire was most active above the inversion, “within a mountainous bowl and ravine on the northeast of the fire, and on the west flank,” the service reported in a briefing.
A temperature inversion occurs when warm air “caps” cooler air, causing smoke to become trapped in a valley bottom.
Crews worked through the day to secure the north flank and tie it into rocky slopes in order to keep the fire from wrapping around towards Keremeos.
Other crews continued work on the east flank to mop-up and patrol along Chopaka Road, and personnel worked to utilize an existing road system in the Roberts Creek area to the south of the fire to develop containment lines and take advantage of existing features.
“Our firefighters have completely burned up into the hillside, so the fire is no longer at a risk of coming down and threatening those properties,” said Ms. Allen.
About 100 firefighters are on the ground fighting the blaze, which was discovered July 17.
“That number is subject to change given that the Snowy Mountain fire is in a complex with the Placer Mountain fire,”” said Ms. Allen. “We do shift resources — both personnel as well as aviation and heavy equipment — between those two fires.”
The crews are being supported by bucketing helicopters.
The fire was estimated Monday to be about 40-percent contained.
With warmer temperatures expected in the coming days, the service is concerned “down-slope” winds might push the fire east.
“If the inversion breaks, we will see temperatures back up into the mid- to high-30s at the valley bottom,” said Ms. Allen.
“That’s really was what the challenge was in the overnight period several days ago. Winds were coming out of the valley top, pushing (the fire) downslope at 50 km/h — or even higher during some periods.”
To ensure properties are kept safe, structural protection specialists will continue to assess properties on the valley bottom, moving south along the Chopaka Road down to the U.S. border.
An Area Restriction Order is in place for the Snowy Mountain backcountry and an evacuation alert remains in effect for areas around Keremeos and Cawston and for homes on Chopaka Road.