Potential localized floods in northeastern Alberta, as rains bring wildfire relief

Environment Canada has issued a rainfall warning for the Regional Municipality of Wood Buffalo, near Fort McMurray and Anzac, Alta. 

It says that rain, heavy at times, and scattered thunderstorms would continue on Friday night. 

Over the past 24 hours, the area between Fort Chipewyan and Swan Hills, Alta., received a large amount of rain — between 75 and 100 millimetres. 

Fort McMurray, however, remained relatively dry, getting five to ten millimetres. 

“Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible,” the warning states. 

Heather Pimiskern, a meteorologist with Environment Canada, said this warning could come to pass in areas “towards the northwest, where they have seen some heavy rain. But for Fort McMurray itself, I think you would need to see the thunderstorm activity over the region for that to occur.” 

Pimiskern on Friday morning said they anticipate “some rain both today and tonight” for the Fort McMurray area. 

“And then by tomorrow afternoon, things should begin to clear out.” 

Pimiskern said five to 10 millimetres of precipitation are expected for Fort McMurray on Friday, with an additional 10 to 15 overnight. 

In a statement to CBC, Regional Municipality of Wood Buffalo said they’re “closely monitoring roadways and underground infrastructure with the current rainfall warning in place.” 

The municipality said the storm systems in the region are designed to manage heavy rains, and have been handling them adequately so far. 

River, with left bank covered in lush grass. Concrete beach in the background. Cloudy sky.
While Environment Canada put Fort McMurray under rainfall warning, significant flooding is not expected in the city. (Dennis Kovtun/CBC)

A high stream-flow advisory is in effect for the tributaries of the Athabasca between Fort McMurray and Lake Athabasca. 

The advisory states that water level rises between one and two metres are possible and low-lying areas adjacent to the river may be impacted, but no major flooding is expected. 

However, the municipality said, they have crews ready to respond if the need arises. 

“Mitigation measures could include removing blockages, replacing manhole covers and  temporary road closures to keep motorists safe and allow room for crews to keep water contained on the street,” the municipality said in its statement. 

Rains helped improve the wildfire situation in the province, said Christie Tucker, an information officer with Alberta Wildfire. 

“Many parts of the province saw rain over the past day, which has lowered wildfire behaviour,” she said on Friday. 

“In fact, we had no new wildfire starts recorded yesterday,” she added. 

“This gives wildland firefighters a chance to make progress containing these fires before conditions dry out.” 

Pimiskern said the weather system that brought rain to northeastern Alberta is likely to begin moving east during the weekend. 

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