A Mixed Bag Heading Towards the New Year

Winnipeg will see a bit of a mixed bag over the next few days with some light flurries, some sun, and more accumulating snow on the way.

Today will bring some light flurries to the region as a weak disturbance moves out of the Red River Valley. Accumulations are expected to be minimal, and the light snow will taper off towards the afternoon as the clouds begin pushing off to the east, allowing a bit of sunshine through the afternoon in Winnipeg. Temperatures will be much milder than yesterday with highs near -4°C, but winds will be quite breezy out of the west to around 30 km/h.

Tonight will bring more cloud across the Red River Valley as temperatures drop to a low near -10°C with a northwest wind at 20-30 km/h.

For Thursday, Winnipeg will be under a weak ridge of high pressure. This will bring an end to the flurries, but won’t have enough “oomph” to actually completely clear things out. Skies will likely remain mixed—with perhaps some afternoon clearing—through the day. Temperatures will be a bit cooler than Wednesday with a high near -8°C. Thursday night will bring increasing cloud and a low near -16°C while winds pick up out of the southeast to around 20 km/h ahead of the next incoming weather system.

The NAM shows a swath of 2-3″ of snow (5-8cm) across Southern Manitoba on Friday.

An Alberta Clipper moving through on Friday will bring cloudy skies with snow that starts by mid-morning and persists through to the evening. Temperatures will climb to a high near -8°C with winds tapering off in the afternoon. By the time the snow stops, another 4-8 cm of the stuff will have fallen. Skies will remain mostly cloudy on Friday night with temperatures falling to a low near -17°C.

Long Range

The weekend is looking fairly seasonal for late December in Winnipeg. Saturday will bring mixed to mostly cloudy skies and a high around the -12°C mark. A disturbance moving through Saturday night will bring a chance of flurries and mark the start of a pattern change. Temperatures will slowly fall through the day on Sunday with a brisk northerly wind.

NAEFS 8-14 Day Temperature Anomaly Forecast — Valid January 3 – 10, 2017

Colder weather is on tap for next week as the Polar Vortex re-establishes itself over the central Canadian Arctic, allowing much colder air to slump southwards. Daytime highs next week will fall into the -20’s with overnight lows approaching -30°C.

This transition will mark a change that will likely persist through the first half of January. Although short1 warm-ups to near-seasonal values are possible, temperatures will largely be below-normal and quite cold.

Winnipeg’s seasonal daytime high is currently -12°C while the seasonal overnight low is -23°C.

  1. Perhaps a single day or so. 

Clipper-Like System To Bring Snow, Threat of Freezing Rain, to Southern Manitoba

A clipper-like system ejecting from the Rockies and set to race eastwards across the Prairies will merge with a low pressure system stalled over Southern Manitoba produce widespread snow over the region Wednesday night into Thursday morning.

Cloud cover will increase late this afternoon as the incoming low pushes into southern Manitoba, with an area of precipitation spreading eastwards across the region. Initial phases of precipitation will likely be rain or freeing rain before switching over to snow in the second half of the night. Temperatures will hover near the 0°C mark for much of the night, bottoming out at just –1 or –2°C.

Freezing Rain Potential for December 9-10, 2015
The best chance for some freezing rain tonight looks to run from the Parkland region of Manitoba, eastwards across the Interlake & Red River Valely towards the Ontario border. Freezing rain will be limited south of the international border.
Freezing rain potential exists, but overall it looks like actual amounts would be fairly limited, with just 1–2mm in the worst-hit areas. This will still be enough to make roads quite slippery, though, so if you’re driving tonight, be sure to take extra care.

Snowfall will be limited south of the Trans-Canada highway and likely more characterized by a passing band of snow, then a pause before wrap-around snow pushes in on the back-side of this system. Further north, somewhere near the Trans-Canada highway, a west to east band of snow will set up along the northern edge of the low track and will produce the most snow, with general amounts of 5–10cm expected. There will be the risk of amounts in the 10–20cm range for localized areas of upslope flow along the eastern slopes of the Riding Mountains.

AWM Storm-Total Snowfall Forecast valid December 10, 2015
A swath of 5-10cm of snow is expected across Southern Mantioba by the end of tomorrow afternoon.
The snow will continue falling through much of Thursday here in Winnipeg and the Red River Valley before tapering off in the evening. The snow will be accompanied by gusty northerly winds of 30 gusting 50km/h. Expect the winds to taper off and skies to clear on Thursday night with temperatures dropping to about –6°C.

Friday will be a relatively nice day, however we’ll be stuck between a low pressure system passing to our south and an Arctic ridge to our north. This will keep temperatures limited to around –3°C for a daytime high and bring a chance of some flurry activity through the afternoon as mixed skies develop over the region. Fortunately, winds won’t be too much of an issue. Clouds will likely hang around on Friday night as we head to a low near –7°C.

Long Range

While the cooler temperatures in the forecast may be disappointing to some who have been enjoying this stretch of incredible early-winter warmth, there’s not too much room for complaining as the overnight lows this week are just dipping towards what the normal daytime high is for this time of year.

There’s some uncertainty as to what the weekend will bring, but overall it should be a fairly quiet weekend with seasonal to slightly above seasonal temperatures. Little to no snow is expected.

NAEFS 8-14 Day Temperature Anomaly Forecast
The NAEFS is forecasting a return to above-seasonal temperatures in the 8-14 day time span.
Over the next week, no additional snow is expected, and again, above-seasonal temperatures are expected to build back into the region. The fresh snowpack that will develop after tonight’s snow will likely preclude significant stretches of above–0°C weather, but with daytime highs dropping by the day, it’s nice that the –30°C deep freeze isn’t anywhere to be seen.

Alberta Clipper Plunges Manitoba Into The Deep Freeze

An Alberta Clipper moving through the province on Friday into Saturday will pack a potent punch – likely the worst storm so far this winter for most places, including Winnipeg – bringing a decent shot of snow alongside strong winds producing significant blowing snow. To cap things off, a bitterly cold air mass will move into the region bringing extremely cold temperatures & wind chill.

-14°C / -21°C
Early morning flurries, then snow beginning late in the day
⇓ -26°C / -32°C
Snow tapering off then clearing; windy & cold
-27°C / -33°C
Mainly sunny

Friday will start off mainly cloudy as a brief shot of light snow exits the province. Amounts from this band will be just a couple cm or less and this leading impulse will be nothing compared to what will be moving in later in the day.

Before that, though, skies will become more mixed with temperatures gradually climbing to around –14°C. Winds will remain relatively light until the Alberta Clipper moves into the region tonight.

Snow will push into Southwestern & Parkland Manitoba this afternoon and quickly spread eastwards across the remainder of the province by the evening. Snowfall will be quite intense, with rates reaching as much as 2cm/hr in the heaviest band. The heaviest snow will fall through Friday night and then taper off from west to east through the day on Saturday.

Expected snowfall totals across Southern Manitoba. The heaviest snow is expected to fall within 50km or so on either side of the U.S. border.
Expected snowfall totals across Southern Manitoba. The heaviest snow is expected to fall within 50km or so on either side of the U.S. border.

By the time the snow tapers off on Saturday, up to 25cm of snow may have fallen through the heaviest band of snow which is centered along the international border and cuts across the Southern Red River Valley. Winnipeg will likely receive on the higher end of 10–15cm of snow while amounts then taper off through the northern Parkland region and central Interlake.

Measuring that snow may be quite difficult, though, as strong northwesterly winds to 40km/h move into the Red River Valley. With all the fresh snow, widespread blowing snow is very likely on area highways with the potential for significant restrictions to visibility. In areas of the southern Red River Valley, we may even see the development of a full-on blizzard with the higher amount of fresh snowfall and slightly stronger winds due to the funnelling of the valley. Driving conditions will likely be quite poor, so be sure to give yourself plenty of additional time if you need to travel and remember to always carry a winter survival kit in your vehicle.

There’s only one story once the snow tapers off on Saturday and skies begin to clear: bitter cold. It’s going to get very, very cold across the entire province with the coldest air mass of the season diving southwards behind the clipper. Saturday will see temperatures slipping through the day to around –26°C which will then plummet down to –32 or –33°C overnight. With winds of 10–20km/h persisting overnight, wind chill values of –40 to –45 will be widespread through Southern Manitoba.[1]

Sunday will bring barely any recovery with temperatures struggling to get to a paltry –27°C. Expect the low on Sunday night to dip back down to –32 or –33°C with wind chills agin in the –40 to –45 range.

No Warmth In The Long-Range

Looking ahead to next week, conditions look dry with little to offer as reprieve from the cold. Daytime highs will moderate towards the –20°C mark, but overnight lows in the low minus-twenties will be sticking around for a while.

The NAEFS 8-14 day temperature anomaly outlook.
The NAEFS 8–14 day temperature anomaly outlook.

Looking even further ahead, there are little in the way of strong signals. There’s about a 50/50 chance of below-seasonal temperatures continuing, but compared to this week, it’s at least a trend towards more seasonal temperatures. It’s not much, but when we’re getting as cold as we will this weekend, I’ll take what I can get.

  1. This will likely result in an extreme cold warning being issued by Environment Canada, as their criteria is a temperature or wind chill colder than –40.  ↩

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.

-11°C / -17°C
Mixed skies with a slight chance of flurries
-14°C / -17°C
Increasing cloud
-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.  ↩