October has picked up where September left off with cool and rainy weather and after a short reprieve this week, temperatures will fall even further and the expected precipitation on the way will likely fall at least in part, as snow.
Temperatures will be the warmest yet to start the week. Monday and Tuesday could end up as the warmest days of the month before the weather turns and Winnipeg and southern Manitoba get ready for some potentially significant snow.
High pressure south of the border will help keep the sky clear and allow temperatures to warm up.
There’s low pressure to near northern Alberta that will move East and a cold front will bring mostly rain Tuesday night. Around this time, another low pressure system is developing near Colorado that will be heading towards southern Manitoba.
As this system approaches, combined with northerly winds will see rain change to snow, and potentially some significant totals, by the end of the week.
Snowfall amounts will be difficult to predict for a few reasons. The first is it is difficult to predict exactly when rain will change to snow. Generally Tuesday night or Wednesday morning is when this switch could happen but where the switch takes place and the exact track of the system are still to be determined.
Typically Colorado Lows follow a track impacting southeastern Manitoba more then the southwest. The southwest is often impacted more by Alberta Clippers.
It’s already been mentioned but it’s worth saying again that there is a wide range in possible snowfall totals around Winnipeg and southern Manitoba. For Winnipeg, as of Monday models show a range from around 5 cm to as much as 20 cm by the weekend. This Colorado Low will be the focus of the forecast all week.