By Rod Nickel

ANZAC, Alberta (Reuters) – A massive wildfire near Fort McMurray in Alberta, Canada, that has grown to five times its initial size has spread south, forcing more evacuations on Thursday after 88,000 people fled the city in the nation’s energy heartland.

The weather forecast has called for cooler temperatures and possible rain, offering hope that controlling the blaze could become easier.Map of the Fort McMurray fire – (http://tmsnrt.rs/1TtvIOD)

Late Wednesday, flames fanned south from Fort McMurray, the main city in Canada’s oil sands region. Officials issued mandatory evacuation orders for the Anzac, Gregoire Lake Estates and Fort McMurray First Nation communities, located about 50 km (31 miles) south of the battered city.

Officials on the scene were forced to evacuate a make-shift emergency operations center for the second time in less than a day.

Authorities said there had been no known casualties from the blaze itself, but fatalities were reported in at least one vehicle crash along the evacuation route.

Thousands bunked down for the night on Wednesday in arenas, hockey rinks and oil work camps that were often short of fuel and food.

Fire also threatened the airport, and web cam images showed black smoke engulfing the area late Wednesday evening. Officials confirmed that a hotel north of the main terminal had caught fire, but as the sun rose on Thursday new images of the airport showed no obvious damage.

Major oil sands facilities were not in the path of the flames, but companies’ efforts to help employees and evacuees and protect pipelines affected production and helped boost the price of crude.

Austrian consultancy JBC Energy estimated that some 500,000 barrels per day of capacity was offline. [O/R]

Hot, dry, windy weather has made the massive wildfire all but impossible to control. The entire city of Fort McMurray was ordered to evacuate on Tuesday, and some 1,600 structures have been destroyed, Alberta Premier Rachel Notley said on Wednesday.

Temperatures hit 31 degrees Celsius (88°F) on Wednesday. But on Thursday morning, Environment Canada forecast a high of 19 degrees Celsius (66°F) with a 30 percent chance of rain. The average high in the area is 15 degrees Celsius.

A government forecast map of potential fire intensity still showed some areas around Fort McMurray at class 6, the highest level.

In the early hours of the evacuation on Tuesday, fire blocked the only route south to major cities, so thousands of evacuees drove north, where there are oil sands facilities but few major settlements, and no route out except back through the burning city.

Late Wednesday, the regional government fielded questions on Twitter from frightened evacuees north of the city, asking when they would be able to drive south, and whether areas north of the city were safe.

“We haven’t forgotten about you and you’re safe,” said the government on Twitter.

(Reporting by Ethan Lou and Allison Martell in Toronto; Editing by Lisa Von Ahn and Jeffrey Benkoe)