Seasonal Weather with a Bit of Snow

Calmer weather is settling into Southern Manitoba after a Colorado Low dumped 10–20cm of snow over the Red River Valley, quickly turning an area that still had substantial amounts of snow-free ground into a winter wonderland.

Today will bring mixed skies to Winnipeg & the Red River Valley as cloud left behind from this week’s storm straggles over the region. Temperatures will be much closer to seasonal than we’ve experienced over the last several weeks. Today’s high temperature will be around –13°C, actually a couple degrees below the seasonal high temperature of –11°C. With some clear patches working their way into the Red River Valley this evening, the overnight low will manage to drop all the way down to a seasonal –20 or –21°C.

RDPS Precipitation Forecast valid 18-06Z December 19/20, 2015
The RDPS shows a swath of snow pushing across Southern Manitoba late Saturday

Saturday will see more cloud spreading into Southern Manitoba as a mid-level disturbance tracks along the international border. As the system approaches, an area of light snow will spread across the region. Total snowfall is expected to be light, with just 1–2cm over the Red River Valley. Further north through the Interlake could see a tad more snow with total amounts in the 2–4cm range. Temperatures will remain cool with daytime highs near –12°C. Winds will be a bit breezy out of the southeast at 20–30km/h.

The extensive cloud cover at night will moderate the overnight low, with temperatures dropping to just –14 or –15°C. The winds will diminish early in the evening.

Sunday will continue with mixed skies, but temperatures will be quite a bit warmer than Friday or Saturday as daytime highs climb towards –8°C with light northwesterly winds. Not much else to talk about for the end of the weekend as skies clear and temperatures dip back into the mid-minus teens on Sunday night.

Looking Ahead to Christmas Week

Next week is looking great considering we’re moving into the second half of December. The northwesterly flow aloft which is giving us this outbreak of more seasonal temperatures is forecast to be replaced by a more zonal (west-to-east) or southwesterly flow aloft, which will help milder air spread over the southern Prairies.

We may see a few bouts of light snow next week while we enjoy warmer-than-seasonal temperatures in the –5 to –10°C range.

Cooler, But Still Mild for December

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.

RDPS 12hr. QPF valid 12Z December 12, 2015
The RDPS is forecasting light snow across much of the Southern Prairies on Saturday night.

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.

NAEFS 8-14 Day Temperature Anomaly Forecast
As has been the almost-permanent state of the NAEFS this winter, above normal temperatures are forecast in the 8-14 day range for Manitoba

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.

Climate Prediction Center's 90-Day Temperature Trace for Winnipeag
The CPC’s 90-day temperature trace for Winnipeg

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.


  1. Record high temperatures have been relatively rare over the past 60 days.  ↩

A Brief Cold Snap Before Weekend Warmth

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.

RDPS Surface Pressure Pattern for 12Z Thursday November 26, 2015
By Thursday morning, a large ridge of high pressure will be moving over Southern Manitoba.

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!

Winter Settles In

After the blustery entrance of winter that saw the first substantial snowfall of 2015 in the Red River Valley alongside winds gusting anywhere from 70 to 90 km/h, significantly cooler weather will settle over the region for the coming days. There good news is that temperatures won’t be too far from seasonal for this time of year, despite being nearly 15°C colder than they were earlier this week.

Mainly cloudy skies will persist through the Red River Valley today with northwesterly winds of 20–30 km/h with gusts up to around 45–50 km/h. The snow we’ve seen the past couple days is over, but a couple light flurries can’t be ruled out through the day; that said, it wouldn’t be much that will accumulate. The only threat of accumulating snow will come as the winds align and lake-effect snow develops off of Lake Manitoba and Lake Winnipeg. Who will see the snow will depend on exactly what the wind direction is, and at the time it looks like Winnipeg may see a bit of snow from these features. Daytime highs will be slightly below the seasonal normal of –3°C, topping out at –5°C or so.

RDPS 12hr. Precipitation Accumulations
The RDPS precipitation totals for today clearly show the two bands of lake-effect snow off of lake Winnipeg & Lake Manitoba.

The clouds will start breaking up tonight as we head towards a low of –12 to –15°C.

Saturday brings less wind, a little less cloud, but more cold. Mixed skies will preside over a day that sees temperatures climbing to –6°C or so and calm winds. The cooler, calmer weather is thanks to a ridge of high pressure that will be sliding through the area. Despite the cooler weather, the lack of significant winds and a bit of sunshine may end up making Saturday a relatively pleasant day overall. Expect a low near –12°C under partly cloudy skies on Saturday night.

GDPS 12hr. Precipitation Accumulation valid midday Sunday through Sunday evening.
The GDPS is showing a large area of snow pushing through Manitoba on Sunday afternoon and evening.

Sunday’s weather will be largely influenced by the approach of the next low pressure system to impact Winnipeg and the Red River Valley. Starting fairly early in the morning, winds will begin picking up out of the south and will strengthen to around 30–40 km/h by midday.[1] Cloud cover will push in from the northwest while temperatures climb close to the freezing mark. By later in the afternoon, it appears that there will be a fairly good chance that the Red River Valley will see an area of snow push through, possibly dropping another couple cm over the region.


  1. At this point, winds of 30–40 km/h seem reasonable, however if a little more cold air damming occurs in the Red River Valley, which will dependent on the exact track and strength of the ridge of high pressure moving through on Saturday, then stronger winds of 40–50 km/h could possibly develop. We’ll keep an eye on it as the weekend progresses.  ↩