Mid-Week Warm-Up Gives Way to a Stormy Return to the Cold

Manitobans can enjoy slight relief from the bitter cold that has been in place the last few days as more seasonal temperatures are in place thanks to a fairly large low pressure system passing through Hudson Bay that has dragged the warm air all the way east from the Rocky Mountains. Unfortunately, the milder weather will be short lived as a series of cold fronts sweep southwards into the United States ushering the colder air back into the region.

Wednesday
-11°C / -17°C
Mixed skies with a slight chance of flurries
Thursday
-14°C / -17°C
Increasing cloud
Friday
-15°C / -19°C
Partly cloudy

Temperatures will climb to around –11°C today with mixed skies as a warm front slides through the region from the northwest. There will be a slight chance of flurries, particularly first thing in the morning and again in the evening into the overnight period, but otherwise it will be a seasonally nice day with westerly winds at 30–40km/h. Expect temperatures to drop to around –17°C tonight.

Thursday will be a bit of an in between day; a weak cold front passing through will bring daytime highs cooler than Wednesday – somewhere around –14°C or so – and a fairly sunny start to the day. By the afternoon, more cloud should begin working its way in from the west alongside the next low approaching from Saskatchewan. Little in the way of snow is expected here on Thursday or Thursday night and winds will be relatively light. Temperatures will dip back down to –17°C once again on Thursday night.

Friday will be the sunniest day of the second half of the week. A slight chance of some morning flurries will quickly clear out as we head to a high of around –15°C with light winds. However, a storm is brewing, and by Friday evening an Alberta clipper will be making its way into Southern Manitoba, set to pack a compact wallop as it moves through Friday night and Saturday.

End-of-Week Alberta Clipper Brings Winter Storm to Manitoba

An Alberta Clipper is forecast to track across Southern Manitoba Friday night into Saturday, bringing with it a significant shot of snow, strong winds, and then a plummet back into frigid Arctic air.

Note: Alberta clippers are compact systems whose impact depends significantly on their track. As we’re still several days out from this system, please take the following as just general guidance and remember that with a slight change in track, significant changes in the weather could be seen for any one location.

Snow will spread eastwards into southwestern Manitoba and the Parkland region on Friday evening, progressing across the remainder of the province through the evening hours. A relatively sharp deformation zone will set up across the Parkland & Interlake regions, limiting the northward extent of the snow. While many regions will see accumulating snow, the greatest amounts will be along the Trans-Canada corridor and the western escarpment of the Red River Valley.

First-guess snowfall amounts for the upcoming storm system this weekend.
First-guess snowfall amounts for the upcoming storm system this weekend.

By the time the snow stops on Saturday evening, around 10–15cm of snow may have fallen in a large swath encompassing much of the Trans-Canada corridor and areas south to the U.S. border. An area of higher snowfall will likely develop somewhere near the US border, perhaps just south into North Dakota, depending significantly on where & when the system pivots and begins heading E/NE instead of SE. In the core of heaviest snowfall, as much as 15–25cm of snowfall looks possible. Much of the Parkland and southern Interlake will see between 4–8cm, with amounts tapering off fairly quickly north of that.

In addition to the snow, this system will have fairly strong winds associated with it. Ahead of the low, easterly to northeasterly winds will strengthen to a gusty 30–40km/h. As the system passes through, winds will strengthen out of the northwest to around 50km/h with gusts as high as 70–75km/h. The strong northwesterly winds coupled with the ample fresh snow will likely produce blizzard conditions and make travel dangerous on Saturday. If you have travel plans, make a plan B in case this forecast happens to be right.

Temperatures will reach a high around –15°C on Saturday and then plummet to around –30°C on Saturday night with wind chill values near –45. Sunday looks clear and bitterly cold with a high of only around –26°C coupled with 20–30km/h winds that will produce wind chill values in the –35 to –40 range. If these wind chill values materalize, we’ll likely see extreme cold warnings issued for much of Southern Manitoba through the weekend.[1]

As mentioned, there is potentially significant variability to this forecast and what I’ve presented is the current most likely scenario. I’ll be keeping tabs on this system through the week and provide updates in the comments below and another full look at it in Friday morning’s blog post.


  1. If the extreme cold occurs while blizzard conditions are ongoing, the blizzard warning would “include” the extreme cold.  ↩

Seasonal Weekend Ahead

Seasonal weather will be in place over the Red River Valley this weekend with dry conditions and comparatively mild temperatures.

Friday
-9°C / -14°C
Mixed skies and breezy

Saturday
-6°C / -8°C
Increasing cloud with late-day wind

Sunday
-3°C / -9°C
Cloudy and mild

Today will be the least pleasant day of the weekend with temperatures climbing to around -9°C with somewhat gusty northwesterly winds – around 30km/h with gusts closer to the 40-50km/h mark – ushering cooler air than we had yesterday. While we’ll see a fair amount of cloud today clearing out in the afternoon, no snow is expected. Temperatures will dip to the mid-minus teens tonight as winds taper off.

Saturday looks like a fairly pleasant day. A ridge of high pressure over the region will bring mainly sunny skies and a high near -6°C. Winds will begin picking up out of the south a little later in the day, making it feel a bit colder but limiting our overnight low to just around -8°C or so. Some light snow is possible late Saturday afternoon into the evening hours ahead of a warm front gradually lifting northwards through the night.

Sunday will be a very mild day that starts off with somewhat unpleasant southeasterly winds. By late morning or early afternoon it looks like the winds will die off and the temperature will climb to a very balmy high of around -2 or -3°C. Some snow is possible in the afternoon, but it looks like the bulk of the precipitation will remain to the north and east of the Red River Valley, with just a light dusting of snow possible. Temperatures on Sunday night continue mild with lows near -9°C.

Pattern Change Next Week Brings More Mild Weather

As we mentioned earlier this week, a major pattern shift covering much of North America will occur through the early half of next week that will move most of the continent into an above-average temperature regime for an extended duration.

The general gist of the pattern evolution is this: over the next few days, a very strong frontal zone over the northern Pacific will shift eastwards alongside a train of upper-level disturbances reflected at the surface by a very intense low pressure system – bottoming out today at 950mb or so. This intense low will become stacked east of the Aleutians and absorb several weaker, more disorganized disturbances, becoming a very impressive, large storm over the northeastern Pacific. This intense system will build an upper-level ridge over western North America, beginning the push of warm air. The second key ingredient is the evolution of the polar vortex that has been anchored over Hudson Bay for the last few weeks.

By this weekend, shown here in the GDPS 500mb height & vorticty forecast, several very potent low pressure systems – marked by the letter L – will begin building a ridge over western North America while the polar vortex – shown by "PV" – begins a slow trek eastwards.
By this weekend, shown here in the GDPS 500mb height & vorticty forecast, several very potent low pressure systems – marked by the letter L – will begin building a ridge over western North America while the polar vortex – shown by “PV” – begins a slow trek eastwards.

Fortunately, a powerful low pressure system heading up the east coast with teleconnections to the polar vortex will help “push” the vortex from its resting place and rapidly shunt it eastwards over Greenland. This is the second key ingredient because the polar vortex over Hudson Bay[1] is what anchors the eastern Prairies into a northwesterly to northerly flow for such long periods of time, reinforcing colder air and shunting warmer air to our south. With the vortex skipping town, the arctic jet stream will retreat northwards and the warm air spreading northeastwards with the upper ridge will be able to spread eastwards across the Prairies unhindered.

It’s a very interesting situation that highlights how stable the ridge-trough pattern that is so common is; in order for us to be kicked out of this pattern that has brought us a very cold November, we need very potent, significant storms on both coasts at the same time disrupting the upper-level pattern enough to get things moving again.

Within the warming pattern, we’ll see relatively warm and cool spells as disturbances ripple across the Prairies , but overall it looks quite dry in the Red River Valley as daytime highs climb into the -5 to 0°C through the second half of next week with the possibility of above-zero temperatures late into the week through the weekend. different from


  1. Its worth noting given how much press the term “polar vortex” gets lately that this is a completely normal feature that is dominant over Hudson Bay for huge swaths of winter every single year.  ↩

A Reprieve From The Cold

A breakdown in the upper-level ridge over Western North America that has locked Manitoba into an unseasonably cold regime for the past 10 days will result in a significant shift in the weather for the coming weekend as warmer air finally makes its way inland from the Pacific coast. The weekend is set to end with a bang as a low pressure system taps into the warmer air and brings the first major widespread snowfall event to the Prairies.

Friday
-3°C / -5°C
Partly cloudy with a slight chance of light late-day flurries
Saturday
-1°C / -4°C
Mostly cloudy
Sunday
0°C / -13°C
Mainly cloudy; snow possible

Today will be one of those slightly unpleasant transition days into a warmer air mass being brought into the region by a low pressure system tracking across the Central Prairies. Southerly winds to 30-40km/h with gusts up to around 50km/h will make things feel a bit chilly, even though we see a warmer-than-anything-recently high near -3°C or so. If the winds manage to shift more southwesterly, then we could see several degrees added onto that high, jumping up to 0 or +1°C, however the deep layer of cold air and outflow from the ridge to our southeast will likely keep things on the cooler side.

There will be a slight chance of flurries late this afternoon into early this evening as the warm front passes by. Otherwise tonight will see mostly cloudy skies as temperatures drop to around -5°C.

Saturday looks like a fairly quiet day. Mostly cloudy skies, light winds and a high near -1°C will make for a fairly pleasant day. Temperatures will drop to around -4°C under cloudy skies and increasing east-southeasterly winds.

Sunday Brings Major Snowfall to Portions of Southern Manitoba


An updated snowfall forecast and look at this weekend’s snow is available in the comments below.


A low pressure system tracking along the International border is set to bring a substantial snowfall to portions of the Parkland & Interlake regions as a weak inverted trough persists through the region for much of the day. Snow is expected to push into Western Manitoba late Saturday and spread eastwards into the Interlake and onwards across the lakes into eastern Manitoba by Sunday morning.

A Weather Moment snowfall forecast for November 22-23, 2014. Up to 20cm of snow is possible through portions of Southern Manitoba.
A Weather Moment snowfall forecast for November 22-23, 2014. Up to 20cm of snow is possible through portions of Southern Manitoba.

Snowfall will be fairly heavy at times, and in general amounts will likely fall into the 10-15cm amount for a large swath from Dauphin to The Pas extending eastwards. For portions of the Swan River region eastwards through the northern Interlake and into Berens River, slightly higher amounts will likely be seen with up to 20cm possible.

Further south in the Red River Valley, some light snow is likely, however there’s some considerable uncertainty in how the evolution of this system will take place which is resulting in quite a spread of results. The general consensus at the moment is that little snow will be seen with amounts generally less than 2cm on Sunday, however some guidance suggests that strong low-level instability and strong lift behind the passage of the cold front in the afternoon could result in fairly intense snow over the region.

As we get closer to the event, we’ll be able to refine this forecast a little more, particularly for the Red River Valley.

Other than the snow, Sunday will be fairly mild with a high near 0°C in Winnipeg while winds starting off relatively light out of the east-southeast backing to northwesterly at a gusty 30-40km/h with some blowing snow in rural areas by Sunday evening. Much cooler air will push in through Sunday night which should allow the overnight low to drop into the minus teens.

Next week looks to start off a little unsettled with some flurries hanging on in Southern Manitoba while another shot of Arctic air begins working into the region.

Another Blustery Day Leads Towards a Pattern Change

Today will be yet another blustery day in the Red River Valley as strong northwesterly winds sit over the region behind a low pressure system that passed through overnight. Blowing snow will be an issue in some rural areas, however little new snow and a couple days of compaction since Sunday’s snowfall should result in less blowing snow than was seen then. After one last shot of cold air settling over Southern Manitoba tonight, the large-scale pattern looks set to change and allow slightly milder air back into the region.

Wednesday
-9°C / -19°C
Mixed skies with a chance of flurries; windy with local blowing snow
Thursday
-10°C / -16°C
Mainly sunny
Friday
-5°C / -9°C
Mostly cloudy and breezy

Today’s most significant weather will be the strong northwesterly winds in place through the whole Red River Valley. Gusting as high as 60-70km/h, the strong winds will make the high of -9 or -8°C feel much colder with wind chill values in the -15 to -20 range. Blowing snow will be a bit of an issue in rural areas, however with little new snow and some time for Sunday’s snow to settle, reduced visibilities in blowing snow should be much less an issue today than it was for the end of the weekend. No significant accumulations are expected today in the Red River Valley, however there may be an isolated band of higher amounts in the lee of Lake Winnipeg.[1]

Tonight will see skies clear and winds taper off as temperatures dip down to a “chilliest-this-season” low near -19 or -20°C.

After a chilly start, Thursday will be another cool day. Fortunately, light winds will make things feel not nearly as bad as Wednesday as temperatures climb towards a high near -10°C. Skies will remain mainly clear[2] on Thursday night as temperatures dip down to around -16°C.

Big Warm-Up in Store for End of Week

After a considerable amount of time with below-normal temperatures, things look set to switch around dramatically on Friday as the upper-level ridge that’s been in place for much of November over British Columbia completely collapses and a zonal flow brings milder temperatures eastwards across the Prairies.

The 850mb temperature & wind forecast for Thursday evening show a clear warm front pushing eastwards across the Prairies.
The 850mb temperature & wind forecast for Thursday evening show a clear warm front pushing eastwards across the Prairies.

The milder air will bring a fair amount of cloud cover with it as it spreads eastwards, resulting in a mostly cloudy day in Winnipeg as temperatures climb to a relatively balmy -5°C or so. Unfortunately, with all the mild air attempting to move in, strong southerly winds to around 40-50km/h will likely develop, keeping things feeling cooler than it would otherwise. There may be a slight chance of some light flurry activity in the Red River Valley along the warm front in the afternoon, but at this point it looks insignificant.

Mild air will continue to push eastwards on Friday night, and the Red River Valley should find itself into the warm sector of this low pressure system. As a result, overnight lows will be considerably warmer than we’ve seen lately. Expect temperatures to drop to around -8 to -10°C on Friday night under partly cloudy skies.

Mild Weekend Ahead

We should see more pleasant weather on Saturday with a fair amount of sunshine and lighter winds as the temperature climbs to around -4°C.[3] Sunday continues the mild trend, however the milder temperatures will be sustained by a low pressure system tracking along the U.S. border.

The GDPS 12hr. precipitation accumulation for Sunday morning to evening shows a large swath of snowfall through Western Manitoba & the Interlake, just brushing the northern Red River Valley.
The GDPS 12hr. precipitation accumulation for Sunday morning to evening shows a large swath of snowfall through Western Manitoba & the Interlake, just brushing the northern Red River Valley.

This system looks like it has the potential to bring a swath of 10+cm of snow to the Interlake westwards towards the terrain west of lakes Winnipegosis and Manitoba. Given how far out this system is, there’s a lot of details up in the air[4] and slight variations in track or intensity could dramatically shift/impact the snow event. We’ll be keeping an eye on it, but for now just keep it in the back of your head that the weekend could be ending with what could be the heaviest large-scale snow event so far this season.


  1. Very little is expected in the way of lake-induced flurry activity to the lee of lake Manitoba now that it’s mainly ice covered.  ↩
  2. Much of the night should be mainly clear, however some cloud may sneak in late in the overnight period associated with Friday’s system.  ↩
  3. The potential for highs closer to -2 or -1°C exists, but I’d rather wait until closer before getting anybody’s hopes up.  ↩
  4. Rimshot  ↩