Petro-Canada gas stations in Kelowna, Kamloops, Edmonton and Calgary are running out of petrol from their parent company, Suncor.

In Kelowna, an employee at the Petro-Canada at Glenmore and Kane roads said they ran out of regular grade gas at 2:45 p.m. PT on Thursday and were out of premium grade by 5 p.m. Similarly, a staffer at the Petro-Canada on Highway 33 said they hadn't run out of gas yet, but they expected to soon.

"We're out of gas and unless we can get it from a third party then we'll be out three to five weeks," said Tianna Byers, an employee at the Petro-Canada on Highway 97 in Kelowna.

"The fire in Fort Mac has reached a place called Wood Buffalo in Alberta, which is our supplier so we can't get any more gas."

Byers said the location she works at ran out of mid-grade gas and diesel yesterday, and out of premium at 8:30 p.m. on Thursday.

She said the shortage is mostly affecting gas stations in ​Western Canada, including B.C.

In Calgary, a Petro-Canada employee at a station on 37th Street S.W. also said they were completely out of gas, and had heard that other locations in the city were as well.

Production issues

"There have been issues both with crude production because of [the wildfires in] Fort McMurray," said Dan McTeague, senior petroleum analyst with GasBuddy.com.

"But most importantly on Friday of last week one of the refineries that supplies gasoline into the B.C. market and into Kamloops and Kelowna experienced an unknown problem in which production has been curtailed."

McTeague said most of the Okanagan's gas comes from Edmonton via Kinder Morgan's TransMountain pipeline, which is he says is usually "jam packed."

He said although he couldn't confirm the shortage was due to the Fort McMurray wildfire specifically, one clue is that pipeline operators recently issued a call for nominations because they had extra space.

"That is really a significant clue given it's rare that it happens," McTeague said.

He said the Suncor refinery in Edmonton processes140,000 barrels of oil a day and supplies gas stations as far as Thunder Bay, Ont.

McTeague said he has heard anecdotally of 20 gas stations shutting down in both Edmonton and Calgary because of lack of supply. He wasn't sure how many have closed in B.C. because of the issue.

Shortage can be predicted, he said, explaining that in the U.S. refiners are required to issue a weekly summary of supply and demand.

"In Canada no such thing is available and apparently it doesn't seem to be on anyone's radar screen and it should," he said.

Gas shortages are rare, McTeague said, but last summer Shell stations were on allocation — meaning their supplies were rationed instead of set by demand.

CBC News has contacted Suncor, but the company has not responded yet.

With files from Anita Bathe and Brady Strachan