Tag: cold

Alberta Clipper to Bring More Snow This Week

Brad Leave a comment

An Alberta Clipper will bring more snow to Southern Manitoba this week. The system will also bring moderating temperatures, followed by another arctic blast.

Map of Tuesday's Alberta Clipper System - NAM Model

Before the Clipper arrives on Tuesday, we’ll see cold weather again on Monday. High temperatures on Monday will be in the high minus teens with light winds. A southerly flow will begin to develop over Manitoba on Monday night ahead of the next low pressure system. The south wind will become quite strong during the day on Tuesday, with wind speeds of 30-40km/h gusting to 50-60km/h in most areas (except in the Red River Valley where speeds may be a bit higher than that). These strong south winds will bring in much warmer air, with highs on Tuesday likely to be in the low to mid minus single digits in most areas. The Alberta Clipper is expected to begin spreading snow into Southern Manitoba on Tuesday afternoon. Areas in western Manitoba can generally expect 2-4cm of snow, with lower amounts the further south you go. In eastern Manitoba the highest amounts are expected, with total accumulation of 4 to 8cm expected (with higher amounts the further north you go). In the Red River Valley generally 2-5cm is expected, with Winnipeg and Selkirk having the best chance at higher end amounts. As the clipper moves past on Tuesday night, north-westerly winds will develop. These winds will be fairly strong, with readings of 40km/h gusting to 60km/h expected. This will generate blowing and drifting snow in open areas on Tuesday night. Blizzard conditions are not expected, but poor road conditions are still probable.

Models are suggesting that we may see another weaker Alberta Clipper pass by on Wednesday. At this point it’s too early to say exactly how much snow it will produce, but it has the potential to produce amounts similar to those experienced on Tuesday.

Beyond Wednesday it’s hard to tell what will happen next. It appears that Southern Manitoba will be right near the boundary between very cold arctic air to the north and somewhat milder air to the south. If this boundary ends up a bit further south than expected we’ll be firmly placed in that arctic air mass, but if the boundary is further north than expected we may get into the milder air. More weak Alberta Clipper systems are forecast to ride along this arctic boundary, so our position near it suggests we may see more light snowfall events later this week.

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.

Light Snow Then A Return To Cold

Brad Leave a comment

Winnipeg seems to have found itself in the firm grip of winter as below-seasonal temperatures dominate the forecast. A low pressure system passing to our south today will bring snow and a slight moderation to our temperatures to near-normal values, but we’ll quickly drop back to well below-normal temperatures.

Storm-total liquid-equivalent precipitation accumulation

Liquid-equivalent (how much water there would be if you melted the snow) precipitation accumulation valid 18Z today.

A weak upper trough will swing through Southern Manitoba today, embedded within a strong northwesterly flow. While temperatures have warmed some 10-15°C aloft over the entirety of the Red River Valley, it looks like the surface warm front will halt part-way between Winnipeg and the U.S. border. Areas south of the warm front (probably areas south of Morris) will be able to tap into a southerly or even southwesterly flow, allowing temperatures to warm possibly as high as -5°C. Unfortunately for areas over the Northern Red River Valley, the warm front will likely remain well to our south, keeping our winds out of the southeast and slowly backing to northwesterly as the system passes by. These wind directions all favour the reinforcement of cold air as they tap into the colder air ahead and north of the low instead of the warmer air south of the low. That means that while there will be a slight increase in temperature from the advection (bringing in) of warm air aloft, a significant portion of the warming taking place over the Northern Red River Valley will be due to heat directed towards the surface from the clouds associated with this low. Highs north of the warm front will sit in the -12 to -15°C range.

Snow associated with this system pushed in overnight and will continue through the morning before tapering off around lunch time. Heaviest accumulations will lay north of the warm front with lighter accumulations south of the warm front. North of the warm front, including here in Winnipeg, we’ll see a total of 6-8cm of light, fluffy snow, while south of the warm front (the Southern Red River Valley) will probably only see a total of 2-4cm. There’s a slight chance that a few lingering flurries will hang on through the afternoon, but accumulations with those would be minimal should they happen.

Temperatures will drop down to around -25°C tonight as the clouds begin to break up and cold air filters southwards again in a northerly flow behind the low. Temperatures struggle to climb above -20°C tomorrow as we find ourselves deep in the cold air once again, some 8-10°C below normal for this time of year.

There are hints that temperatures may begin to moderate on Friday into the weekend, climbing as high as -9°C on Saturday, as a weak south/southwesterly flow develops. I’ll bite my tongue for now as models can sometimes be overly enthusiastic on moving the cold air out of the Red River Valley, but it does look like it’s at least a possibility. If that flow does develop, it’s likely we’ll see another batch of snow late this week as the warmer air pushes in. Until then, keep the long johns handy and be sure to check back in the comments below or follow along on Twitter for updates as the week progresses!