With high winds Thursday expected to fan more than 270 wildfires burning across B.C., fire officials are bracing for another day of difficult conditions.

Residents have been asked to stay out of the B.C. backcountry and hundreds of homes have already been evacuated, as a cold front is expected to deliver high winds that could worsen the situation.

"Strong winds will fuel existing fires and lightning may spark new fires. In addition, strong winds may prevent air operations and heavy smoke may impair the ability of ground crews to respond," said a statement from the B.C. Wildfire Management Branch website.

The Ministry of Environment has issued its latest smoke advisory for the Kamloops area after smoke covered the city and surrounding areas this morning.

On the air quality scale that normally goes from one to 10, the cities of Quesnel, Williams Lake and Kamloops have all been rated at 11 for expected air quality today.

Officials will be keeping a close eye Thursday on the weather in an area south of Prince George, near Williams Lake, said Stephen Waugh, emergency program co-ordinator for the Central Coast Regional District.

"The hardest hit areas seem to be in the Cariboo Chilcotin region where there were extreme fires burning before these winds arrived. So the morning will tell us how things are looking in that region," Waugh told CTV's Canada AM from Bella Coola.

The latest evacuation orders affect residents near Meldrum Creek, Meldrum East Fraser, Soda Creek/Williams Lake, McLeede Lake and Westwick Lakes, according to a statement posted Wednesday on the district's website.

Waugh said hot, dry weather and high winds are a bad mix.

"Our forest minister described it as perfect firestorm conditions," he said. "When you have fires burning aggressively already and then have high winds on top of them it really does make things difficult for fire crews, and many were pulled off yesterday for safety reasons."

Waugh himself has been trapped in Bella Coola, B.C. for days. The isolated town has just one road in and out, and it has been shut down to traffic since Sunday night.

"There are worse places to be trapped," he said. "Bella Coola is a beautiful spot to be and fortunately we're safe. … But it's been a while and people are managing but their patience is being tried."

The hot, dry summer has left some 279 forest fires raging across British Columbia at last count. A full 71 per cent of the province is at high or extreme risk for forest fires, twice as much as last year.

Air quality has plummeted across the province as fires spew hot ash and smoke into the air.

With files from The Canadian Press