It is beginning to look like our warm weather may end more viciously than anticipated a few days ago. A low is expected to form over the US rockies over the next 24 hours and move east/northeastwards. The question right now is just how far north and west this system will move, to determine how Manitoba will be impacted.
The problem is that this system will bring in very cold air from the north, meaning that a lot of the precipitation to the northwest of the system's centre will likely be in the form of snowfall. And this snowfall is expected to be heavy, and significant accumulations are not out of the question. In addition, winds gusting over 50 km/h are likely, which would give serious travel problems. Due to many differences among the models, there is not much more I can say until later tomorrow. I can warn you however that you may need your shovels in the next 3 days... or maybe not! It will depend highly on the track of the system. Will keep a close eye!