At the same time, trains that are shipping crude out of the pipeline-bottlenecked region must move slower in the chillier weather. Local demand for the oil is also threatened. On Tuesday, operations at Imperial Oil Ltd.’s refinery near Edmonton were disrupted due to the cold weather, the company said.

Natural gas supplies to parts of the oil sands-producing region, where the fuel is used to make steam for loosening bitumen so it can be extracted, were also disrupted on the NOVA Gas Transmission system as “extreme cold weather that has resulted in reduced receipts, high Intra demand and unplanned outages,” according to a notice from TC Energy Corp.

“The cold weather across the province is resulting in the inability for some customers to produce gas onto the NGTL system, while the system is experiencing peak demand,” TC Energy said in an email. “As a result, some central and northeast Alberta industrial customers are affected by lower-than-usual gas pressures.”

Shortfalls of gas supplies have also affected some power generators in the province, said Tara de Weerd, spokeswoman for Alberta Electric System Operator, which manages and operates the Alberta power grid.

Oil sands benchmark Western Canadian Select’s discount to West Texas Intermediate futures was at $24.50 a barrel on Wednesday, the widest in more than a year. Edmonton Mixed Sweet crude’s discount is also at the weakest in more than a year as is light synthetic crude that’s produced from oil sands bitumen processed in an upgrader.

To be sure, oil is facing more headwinds than just the weather, Birn said. Inventories rose to a record in November after a pipeline shutdown and rail strike, according to Genscape. Stockpiles remain at “very high levels,” which means that even as pipeline takeaway and rail capacity increases, there are few “shock absorbers” to deal with sudden disruptions.