Some B.C. wildfires show aggressive behaviour as crews brace for more hot weather

Officials with British Columbia's wildfire service say low humidity and hot temperatures arriving this week are fuelling aggressive activity at some fires.

That's after a modest reprieve from lightning strikes and higher winds had reduced the number of new fires that started in recent days as crews battle some 250 wildfires across B.C.

Forrest Tower, a spokesman with the wildfire service, says the out-of-control Sparks Lake fire northwest of Kamloops has grown to nearly 655 square kilometres.

At a public update event hosted by the Thompson-Nicola Regional District, Tower saidthere has been "some very extreme fire behaviour" at the northern part of that fire, but the priority is ensuring the fire doesn't threaten communities to the southeast.

He addedthat aggressive fire behaviour has also been seen around the southern flanks of the nearly 198-square-kilometre Tremont Creek fire south of Ashcroft.

The 200-square-kilometre White Rock Lake fire burning to the northeast of Merritt is also seeing significant growth because of the weather, and the Columbia Shuswap Regional District says extremely smoky conditions have made it difficult for aircraft to get above the fire.

He says the combination of hot temperatures and a drop in relative humidity means fires are expected to be more intense and the effect of any wind will be amplified.

"We may get a bit of a break from the wind as this ridge kind of has a stable air mass over these fires, but the added challenge isthat even if it may not be strong winds, any wind will have a significant influence on these fires," Tower said Wednesday.

Crews are doing planned ignitions to reduce fuel in the paths of those fires, he said.

If they can establish control lines to prevent the Sparks Lake fire from spreading to the southeast, he said, that's when the wildfire service could recommend that the regional district start thinking about downgrading evacuation orders.

There are nearly 40 other fires of note burning across the province as ofWednesday, meaning they are highly visible or posea potential threat to public safety.

The latest data from the province shows more than 60 evacuation orders covering3,375 properties, while more than 18,000 other properties are on alert.

Environment Canada has issued heat warnings for most of the inner South Coast and special weather statements for many other regions of the southern Interior. Temperatures are expectedto reach the low- to mid-30s near the coast and the upper 30s inland, with only modest cooling at night and little relief until Sunday.