The wildfire still raging near Fort McMurray, Alberta, has a high potential to double to half a million acres by the end of the day Saturday, Alberta wildfire officials said in a press conference Friday evening.

"Substantially extreme fire conditions" will persist for the next several days, Alberta fire manager Chad Morrison said, and firefighters expect the blaze to continue growing - to at least 500,000 acres - into a sparsely-populated forest area northeast of town. 

Weather conditions will likely continue to make things difficult for the firefighters on the ground, said weather.com meteorologist Tom Moore.

"There's a cold front approaching the area, but unfortunately, it's not bringing much moisture," said Moore. "Saturday the high will be in the low 80s, with light winds from the southeast, probably not much more than 10 mph. Sunday will see much cooler temperatures, but wind speeds will be steady at 20 mph from the northwest with the possibility of gusts up to 30 mph."

By Friday evening, the fire had grown to 250,000 acres – a size larger than the city of Chicago – and had already burned structures in the neighboring town of Anzac, Alberta Municipal Affairs Minister Danielle Larivee said.

"The weather is not cooperating with us right now," Larivee said. "These communities are not safe." Officials put a convoy of vehicles in motion Friday morning to move hundreds out of an area north of the city. The convoy was needed because some 25,000 people fled north of the city when mandatory evacuations were issued and became trapped due to a highway closure. Around 1,200 vehicles were able to move southward on Highway 63 Friday, Larivee said, even though officials had to halt evacuations for an hour due to heavy smoke on the highway.

"The reality is that we want to keep Highway 63 open and flowing as long as we can," said a Royal Canadian Mounted Police spokesperson. "Our goal is to move all of the 25,000 evacuees in the north to the south."