Published Wednesday, December 23, 2020 6:22AM EST
The statement was issued by the national weather agency Wednesday morning shortly before 5 a.m.
Rain is forecast to begin Wednesday night ahead of an approaching low pressure system.
The rain is expected to continue into Thursday and become heavy at times, Environment Canada says.
A total of 15 to 25 mm of rain is likely to appear.
By Thursday night, the rain is expected to change over to snow following a strong cold front.
Environment Canada says a few centimetres of snowfall accumulation will be possible Thursday night through Friday morning.
“There remains considerable uncertainty as to the exact track of this low pressure system and the timing of the changeover from rain to snow. This will ultimately affect how much snow may fall at any particular location,” reads the statement from Environment Canada.
The agency warns that drivers should be prepared for “deteriorating winter driving conditions” in areas that receive snow Christmas Eve into Christmas Day.