Fort McMurray wildfire 'may be turning a corner,' official says

(CNN)The massive wildfire that forced the evacuation of almost 90,000 people in Alberta shows signs of slowing down, thanks to the hard work of firefighters and a turn in the weather.

A cold front did not bring expected showers Sunday night, but the area did see lower temperatures and more humidity.

If the rain does come -- and there is a 40% chance of showers Monday morning -- relative humidity will increase over the week, helping firefighters. Temperatures are predicted to hover in the mid-50s through midweek.

The fire had burned about 398,326 acres as of Sunday morning -- quite a bit less than predicted, Alberta Premier Rachel Notley said at a news conference. The day before, fire officials said they expected the fire to double in size to about 494,000 acres."We're very happy we've held the fire better than expected," Chad Morrison of Alberta Fire said. "We hope to see continued success over the next few days. For us this is great firefighting weather."

"We may be turning a corner but its too early to celebrate," said Ralph Goodale, federal minister of Public Safety and Emergency Preparedness. "This beast is an extraordinarily difficult problem."

The slowdown of the fire is the best news Canadian officials have shared since the fire started May 1.

The blaze is huge -- half the size of Rhode Island -- and has destroyed at least 1,600 structures and forced the evacuation of almost 90,000 people. Smoke has been spotted as far south as Florida and could be seen from space.Many of those evacuees left Fort McMurray for oil camps to the north. But the oil companies started evacuating their own employees, so the residents had to be moved again.

"Our key goal yesterday was to complete the evacuation of the 25,000 residents who fled to the north of Fort McMurray, and I'm pleased to say this succeeded," Notley said.However, two people died in traffic accidents during the evacuation, she said. Those are the first fatalities directly related to the fire.

Morrison said firefighters had stopped the fire from reaching oil camps north of the evacuated city of Fort McMurray. He said some oil companies partially evacuated their employees but the camps have the advantage of not having a lot of trees around them, plus industrial fire crews are usually in place.The blaze has not reached the neighboring province of Saskatchewan, but it's heading in that direction.

"It is 30 to 40 kilometers from the border of Saskatchewan, and we're working closely and collaboratively with the Saskatchewan government to assist them with their preparations," Notley said.

Notley said she'll visit Fort McMurray on Monday and some journalists will go with her to see the devastation. Crews have arrived to restore the utility grid in the city, she said. Residents have been told they won't be allowed to return for a long time.Five hundred firefighters employing 15 helicopters and 14 air tankers have been struggling to contain the massive blaze in the Fort McMurray area. Firefighters from Edmonton and other cities are pouring into to help out. In all of Alberta, about 1,500 firefighters are working.

Russia has offered to send aircraft to help fight the fire, according to the country's state-run Sputnik News. Canadian authorities are reviewing the proposal, Sputnik said.

Fort McMurray was under a mandatory evacuation order, along with Anzac, Gregoire Lake Estates and Fort McMurray First Nation.

Fort Mackay, about a 45-minute drive north of Fort McMurray, is under a voluntary evacuation order. Already, 60 vulnerable residents have been moved while about 450 residents remain, Notley said.

The cause of the blaze remains under investigation, according to Alberta Agriculture and Forestry.