Environment Canada is warning of a Significant winter storm expected late this week into the Christmas holiday weekend.

Precipitation may begin as rain or snow late Thursday before possibly transitioning to rain in many areas early Friday. Temperatures are expected to plummet on Friday leading to a potential flash freeze for locations that receive rainfall. Rapidly falling temperatures will be accompanied by strong to potentially damaging winds along with snow that may be heavy at times.

A multi-day lake effect snow event is expected into the weekend in the wake of the system for locations east of the Great Lakes. Blizzard conditions are possible late Friday into the weekend for areas downwind of Lake Huron and Georgian Bay.

Weather officials say that while there is high confidence in a high-impact winter storm, the details regarding wind speeds, precipitation types and amounts remain highly uncertain at this time.

They say to consider altering plans through the holiday weekend as travel conditions may become dangerous. Extensive utility outages are possible. Temperatures Friday night into the weekend will likely be the coldest of the season to date.