Slightly cooler temperatures have moved into the Red River Valley, but they won’t be enough to break our trend of unseasonably warm weather as daytime highs and lows continue to sit between 5 to 10°C above normal. Alongside the cooler but still relatively mild weather will be a whole lot of cloud and a chance for some more snow across the region.

Today’s weather will be predominantly influenced by a ridge of high pressure extending from the high Arctic southwards through Nunavut, Manitoba and into North Dakota. Unlike some Arctic ridges, this one is fairly weak, and as a result, instead of crisp blue skies and bone-chilling cold, we’ll see grey skies, cool easterly winds, and a slight chance of flurries.

With all the cloud cover entrenched over the region, temperatures today will be fairly mild. Daytime highs through the Red River Valley should end up sitting around –1°C.

Another shot of light snow is in the cards for tonight, however, as a band of snow slowly spreads northeastwards out of the United States. The snow will develop and through the day on the U.S. side of the border as a low pressure system, ejected eastwards from yesterday’s explosive Pacific-coast storm, develops through the Northern Plains. The band of snow will slowly push to the northeast and move into southern Manitoba through the overnight period. For most places, less than 1–2cm is expected, however near the U.S. border, slightly more may fall, totalling up to 2–4cm by Saturday morning. Expect an overnight low near –5°C.

Saturday will bring more cloudy skies and widespread light flurry activity. Temperatures will continue to be mild with daytime highs around –2 or –1°C, which when combined with the fact that there won’t be much wind to speak of, will make for quite a pleasant December day. The flurries will taper off in the evening as temperatures dip just a few degrees to about –5°C.

Mild weather continues on Sunday under cloudy skies as slightly warmer air builds into the southern portion of the province. Daytime highs will climb 1–2°C higher than Saturday and sit near the freezing mark with relatively light northeasterly winds. No organized snow is expected on Sunday, so all in all, it will likely be a pleasant end to the weekend! Expect temperatures to dip to around –5 to –7°C on Sunday night.

Long Range: Does the Warmth End?

This section of the forecast has been a broken record so far this winter: continuing mild. And, at the moment, that’s not going to change. In fact, over the past week and a bit, several agencies have re-run seasonal forecast models for North America and they all continue to forecast the same thing: generally mild weather with below-normal precipitation.

This large-scale seasonal outlook has been faring quite well so far this year. The end to this year has been exceptionally mild for Winnipeg; perhaps not in magnitude[1], but just through the sheer persistence of moderately above-normal temperatures.

Since the beginning of November, there have been just 4 days with below-normal daily temperatures and over the last 90 days, just 16. In a place that’s known for large temperature ranges, it’s impressive to think that over 80% of the past 90 days have been unseasonably warm. This incredible warmth led to the 4th warmest fall on record with a mean temperature 3.0°C above normal. By all accounts, this trend looks to continue and that the remainder of the winter, although likely to have occasional cold spells, will generally be a mild one.

The passage of a low pressure system to the east of Winnipeg this morning will usher in cooler air as an Arctic ridge of high pressure builds in across the Prairies. As the ridge builds over Manitoba, temperatures daytime highs will end up falling quite a bit below the seasonal value of –5°C for this time of year, possibly not even breaking the minus double-digits on Thursday. The colder weather will be short-lived, however, as a potentially breezy Saturday holds promise of returning above-seasonal temperatures to the region just in time for the 103rd annual Grey Cup on Sunday.

Temperatures will be on a downward slide today as northerly winds to around 30km/h—with gusts up to the 50km/h mark—usher in cooler air and a large ridge of high pressure sourced from the Arctic. There will be some light snow or flurries around this morning, but they’ll be light and should taper through the morning. By supper time, temperatures will have fallen to around –7°C with the northerly winds still blowing. Heading into the overnight period, the winds will start to taper off with the cloud cover breaking up a bit, but there will be plenty of cloud streaming southwards off Lake Manitoba & Winnipeg through the night.

Thursday may end up being the coldest day so far this November with temperatures struggling against the Arctic air entrenched over the region. Temperatures will climb to around –10°C by the afternoon with winds out of the north to around 20km/h. Skies will be partly cloudy thanks to a continued stream of cloud cover coming off of the lakes, in particular Lake Winnipeg. If you find yourself underneath any of the lake cloud, you’ll likely see some snow, however it looks fairly light and probably won’t accumulate much. Temperatures will dip to only about –13°C on Thursday night as slightly warmer air begins moving in as the ridge slumps to our south.

Seasonal weather will return to Winnipeg on Friday with mainly sunny skies and a high near –6°C. Winds will be fairly light. Temperatures will fall to around –9 or –10°C on Friday night with winds picking up out of the south.

Looking Towards the Grey Cup

The story for this weekend will be warmer weather returning to Southern Manitoba. On Saturday, gusty westerly winds will bring daytime highs approaching –2 or –3°C.

Grey Cup Sunday is a bit of a trickier forecast at this point, but the best guess I have this far out is that temperatures will likely be seasonal with a high somewhere near –6°C or so and light winds. By the time the football game starts, temperatures will probably be somewhere near the –10°C mark, so bundle up!