A forecasted shift in winds could worsen an enormous wildfire burning near a small northern Alberta town.

The concern comes after a “lucky” week of firefighting pushed the Chuckegg Creek fire away from the town of High Level.

“We have been pretty lucky this past week,” said Alberta Wildfire information unit lead Christie Tucker on CTV News Channel Sunday. But the fluctuating winds, combined with high temperatures and humidity, could make the flames more difficult to fight. The fire spans an area of more than 1,000 square kilometres.

“We’re looking at very challenging firefighting conditions,” said Tucker. “We’ve got extremely low humidity. We’ve got high temperatures and we’re looking at gusting winds that could change speed and direction.”

Some 5,000 people were evacuated from the area, and won’t likely return home before later this week.

The weather conditions could also affect other wildfires in Alberta, where there are currently four designated “out of control.”

“Wind is very, very important when fighting any kind of wildfire. It really changes how far the fire can travel and which direction it goes,” said Tucker, adding that crews prepared all week for changing conditions.

“We have put in a few measures that we think will slow down or stop the fire if it starts to move towards the town,” she said. “We’ve also called in reinforcements.”

The crews have used the time to conduct controlled burns and create barriers in an attempt to help shield the town and protect vital communications towers.

The Alberta crews are supported by at least 28 helicopters as well as various types of heavy equipment, and have amassed a team of more than 400 firefighters from coast to coast, including workers from British Columbia, Ontario and Prince Edward Island. The support is much needed for local crews, who have been working long hours to fight the fires, and may have friends and family affected.

“They are probably worried about their own homes,” said Tucker. “One of the benefits of having crews come from elsewhere to help, is that these firefighters who have been working so hard will get a bit of a break. We don’t want to burn people out.”