A Weather Moment

Southern Manitoba will finally see a reprieve from the icy grip of winter as a major pattern change will allow Pacific air to wash over the Prairies bringing substantially warmer – and more unsettled – weather.

Friday

-17°C / -20°C

Mainly cloudy. Chance of flurries this evening & overnight.

Saturday

-14°C / -23°C

Mainly cloudy; chance of morning flurries.

Sunday

-9°C / ⇒ -9°C

Strong winds with blowing snow. Chance of snow late day.

A Couple Cool Days

There will be a chance to dig out after Wednesday night’s storm dumped around 10-15cm through most areas in Southern Manitoba as cool, fairly benign weather settles in over the Red River Valley for the next couple days. Mainly cloudy skies will persist through much of the day today as we climb to a high of only around -17°C.

A weak disturbance will push through tonight that will push some light snow through the Interlake, but further south in Winnipeg & the Red River Valley there will be just a chance for some flurry activity. The relative weakness of the disturbance combined with quite cool temperatures will ensure that if anything manages to develop it will be quite light and not really accumulate to much at all. We’ll remain cloudy through the night and drop to a low around -20°C.

Saturday will be a fairly quiet day with any possible flurry activity tapering off in the morning and then seeing clouds slowly try to break up through the day. Some clearing should work it’s way in later in the day, but it’s a little uncertain how clear we’ll get. While it will have little bearing on any significant weather, it will dramatically affect our overnight low. If we remain a little cloudier – which I’m thinking is the more likely outcome – we’ll see an overnight low of around -23 or -24°C. If the clouds manage to clear out, even for a couple hours, we’ll get quite a bit colder than that and possibly see another low dipping below -30°C. That marks the last day of cold, though, as a major pattern change begins on Sunday.

Wind and Blowing Snow Usher in Warmer Weather

Sunday will mark the beginning of a major pattern shift that will see the persistent trough that’s been anchored over Northwestern Ontario break down and push off to the east, allowing our upper-level northwesterly flow to be replaced by westerly flow. That sounds like a small shift, but the impact will be dramatic.

Sunday will see increasing cloud through the day as milder air finally pushes in from the west. By evening our temperature will rise to around -10°C and snow will be pushing into Southwestern Manitoba. There will likely be at least some flurry activity, if not some light snow on Sunday night as a warm front pushes across the Red River Valley, but accumulations – at this point – look minimal.

Perhaps the biggest weather impact on Sunday will be the southerly winds that will develop through the Red River Valley ahead of the warm front. A tight pressure gradient will result in strong winds developing fairly early in the day. We’ll likely see winds climb to around 50km/h sustained which will undoubtedly produce localized white-out/blizzard conditions in the Red River Valley. It’s too early to say exactly how bad it’s going to be, but it seems fairly certain that blowing snow is going to be a big issue for anyone planning to travel on Sunday, especially in the evening hours when the strong winds may combine with falling snow.

After we make it through the cold weather’s last stand, a significantly warmer – and more unsettled – week is ahead of us as the westerly flow aloft establishes itself over the Prairies. Daytime highs next week look to sit around -4°C, plus or minus a few degrees, but with the warmer weather will come multiple chances for snow as a train of disturbances set up and track across the Prairies. At this point, however, I’ll gladly take more snow if it means a break from the relentless cold we’ve seen in Winnipeg this winter.