Tag: Snow

A Little Snow Before The Coldest Weather This Winter

Brad Leave a comment

Two batches of snow followed by the coolest temperatures of the winter are in store for Southern Manitoba over the next few days.

Clipper Snowfall Totals

Forecast snowfall totals from this clipper system across Southern Manitoba.

An Alberta Clipper will begin it’s march across the Prairies today, rapidly moving from Northern Alberta east-southeast into Northern Minnesota by tonight. This system will drag a warm front eastwards across Southern Manitoba, spreading 1–2cm of light snow across the Red River Valley. The snow will ease off this afternoon to just scattered light flurries as the weak leading impulse moves off into NW Ontario.

Temperatures will warm to around –8°C by this afternoon, with the warmer daytime highs near 0°C locked into the extreme SW portion of the province. A second shot of snow will push into the Red River Valley tonight as the main low centre of the Alberta Clipper moves through the region. Temperatures in the RRV will rise to –4 or –5°C by midnight before starting to drop as the cold front moves through. The bulk of the snow will start near midnight and taper off on Saturday morning with a further 3–5cm of snow accumulation for a total of 4–7cm by the time this whole system moves through.

A few flurries will be around on Saturday as Arctic air begins building into Southern Manitoba yet again. Fairly strong northerly winds gusting up to 60–70km/h will develop early Saturday morning which will result in significant blowing snow in the RRV outside the City of Winnipeg. “Ground blizzard” conditions will be relatively widespread, with particularly poor visibilities as low as 100–200m on west-east running roads, such as the Trans-Canada Highway from Winnipeg to Portage La Prairie. Given the already slick conditions of many roads around the province, be sure to give yourself plenty of extra time if you need to travel on Saturday. The winds will lighten up by mid-afternoon, marking the start of our entry into a major deep freeze. Bitterly cold Arctic air will be pushing southwards behind this clipper system, with temperatures falling to around –25°C by the end of the day. Temperatures will plummet tomorrow night, with overnight lows through the Red River Valley dropping to the –30 to –35°C range. Temperatures will rebound slightly on Sunday as a weak disturbance brings some cloud and a chance of a flurry or two, but even colder air looks to be pushing in on Sunday night.

If the models are to be believed (which I do have some hesitation at the moment), temperatures will drop through the day on Monday to nearly –30°C by the end of the day, with overnight lows dipping to nearly –40°C. I think that the models are getting a little too excited about how cold it will get. The GEM-GLB model’s overnight lows have been 5–6°C too cold over the past week, so it’s more likely that we’ll see lows closer to –35°C than –40°C. At that point, though, it’s colds enough that those numbers don’t even matter. It’s certainly going to be an extremely cold start to next week.

A Cold Second Half to the Week

Brad Leave a comment

Winnipeg will round out the second half of the week with some sun, some cloud, and and very cold temperatures.

Gonna be cold!

You might want one of these for the next little while…

On the backside of yesterday’s system that brought a quick 2–3cm of snow to Winnipeg, a deep pool of bitterly cold Arctic air is infiltrating southwards into the Red River Valley. With sunny skies and a breezy north wind, temperatures will plunge back below the –20°C mark today, bottoming out early this afternoon around –23 or –24°C. Winds will (mercifully) ease off around lunch time, which will minimize wind chill. Temperatures will drop further tonight, with overnight lows dropping below –30°C entirely possible through the Red River Valley, although Winnipeg will likely bottom out at “only” –28 or –29°C.

850mb Temps Thursday Morning

850mb temperatures for Thursday morning from the GFS model. A sharp boundary will slice across the Prairies with pleasant, mild air over the southwestern half and bitterly cold Arctic air over the northeastern half.

Thursday will bring another cold day with plenty of sunshine. The daytime high will struggle to reach –22°C with a light wind out of the south that will increase to around 20km/h by the end of the day. This will keep things feeling closer to around –27 or –28 for much of the day. Proving that the weather can be merciful at times, clouds will begin to roll in Thursday night ahead of the next push of warm air from Alberta. The timing of the cloud cover will strongly impact what the overnight low will be; the sooner the clouds move in, the warmer the overnight low is. At this point, it looks like the temperature will bottom out around –25°C.

Why do clouds impact overnight lows? Clouds can make a big difference for two reasons. First, they act like a big blanket; as the ground radiates heat upwards and cools off, instead of escaping off into the upper atmosphere, it is trapped closer to the surface. This dramatically slows the rate the temperature will cool off. Secondly, clouds radiate heat, generated through internal processes and absorption of the energy the surface is releasing, towards the ground. This also helps to slow down how quickly the temperature drops, or in some cases, even warm it up a little.

On Friday we’ll be under the influence of the next impulse coming across the Prairie. While we won’t get to see the warm air with this system, it’s proximity to us will at least warm us up to around –13 or –12°C. There will likely be periods of light snow across most of the Red River Valley with 2–3cm accumulations likely by the end of the day.

Light snow will persist through the night into Saturday morning. Saturday will bring with it gusty northwesterly winds as things clear out and that bitterly cold Arctic air re-establishes itself over the region. Up to another 2–3cm are possible on Saturday before things clear out. Sunday looks to be sunny and very cold, with daytime highs near –24°C.

The “Meteorological Cliff”

Scott Leave a comment

After a week of relatively pleasant, albeit somewhat sloppy, weather in Southern Manitoba we’re headed for a kind of meteorological cliff. Our weather will change dramatically this Friday, as colder and snowier weather moves in.

Location of the

Before we head off this cliff, our weather will remain very nice. High temperatures on Wednesday will be in the low minus single digits in Southern Manitoba. There may even be a few zero degree readings in south-western sections of Manitoba late in the day as warmer air surges into Manitoba. On Thursday we should reach our warmest temperatures of the week with values in the low (positive) single digits expected. Some of the traditional warm spots in Southern Manitoba may reach values slightly warmer than that. The daytime hours of Thursday will be fairly nice in most of Southern Manitoba, but conditions will begin to change in the afternoon in western areas as snow begins to move in.

Our trek off the meteorological cliff will begin on Thursday night, as snow develops over Southern Manitoba. The snow is expected to begin on Thursday afternoon (or early evening) in Western Manitoba, eventually moving spreading through the remainder of Southern Manitoba by late Thursday evening or very early Friday morning. Total accumulations from this initial batch of snow will generally be in the 2 to 5cm range in Southern Manitoba. By Friday morning temperatures will have fallen into the mid minus teens over much of Southern Manitoba. Snow is expected to taper off from west to east in Southern Manitoba on Friday morning, with south-eastern sections seeing snow linger the longest. The second wave of snow moves in on Friday night. This wave will be generated as a strong Colorado Low system moves up from the south. At this point it appears that this secondary wave of snow will bring another 2 to 4cm to Winnipeg and another 4 to 8cm to south-eastern Manitoba. It is entirely possible that the amounts from this secondary area of snow could be higher or lower than listed above. Depending on where the system ends up tracking Winnipeg could end up with more snow, or perhaps none at all. However, I do believe south-eastern Manitoba will receive some snow during this time period, though again it could be more or less than I have listed above.

Location of the

A secondary concern will develop on Friday as strong north winds develop in response to the intensification of the Colorado Low. At this point it appears that northerly winds of 40km/h gusting to 60km/h, or maybe even 50km/h gusting to 70km/h on a more localized basis, will materialize on Friday. This could create significant travel difficulties as blizzard conditions, or near blizzard conditions may develop as these very strong winds interact with the fresh snow. It is too early to say exactly how bad things may get, but this is certainly something that will need to be monitored closely over the next few days. Please continue to check back with A Weather Moment for further updates on this developing weather story.

After this Colorado Low passes by, conditions will turn calm, but cold. At this point most models keep us in very cold air for basically all of the next ten days. Arctic air doesn’t make a habit of moving around very quickly, so it is likely that we’ll remain in this arctic air mass for an extended period of time. There may be some warmer days here and there, but those details are not yet known with any certainty.

Enjoy these last couple warm days, as winter is quietly waiting to push us off the meteorological cliff.

A Break From Winter

Brad Leave a comment

This week will feature a much needed break from winter, as temperatures soar to well above seasonal values.

Surface Temperatures

Temperatures on Monday will reach the mid minus single digits in Southern Manitoba. There will be a fairly stiff west wind in place throughout the day though, which will make conditions considerably less comfortable than they would otherwise be. On Tuesday we’ll have our first shot at the 0C mark this week, as a low pressure system brings in a warm surge of air from the west. Unfortunately there may be some snow on Tuesday associated with the low pressure system. Amounts will not be particularly high, probably no more than a few centimetres in most areas. Despite the small amounts there could be travel difficulties as the snow is likely to be wet in nature and could present icing issues.

On Wednesday temperatures will remain warm, with highs just slightly below the freezing mark in most areas. We’ll have our best shot at getting above zero on Thursday as a big push of warm air moves into Manitoba from the south-west.

At this point it appears that this warm spell will end on Friday, with a low pressure system passing to our south prompting another arctic air mass to descend into Southern Manitoba. This system may bring a decent snowfall to portions of Southern Manitoba on Friday as well, though it is too early to discuss the details of it. In the longer range most indications suggest that we are in a for a very cold period through the middle of January, with a significant arctic air mass settling over the Prairies. With that in mind, there is all the more reason to enjoy this week’s pleasant “break” from winter.