Tag: Below-Normal Temperatures

A Cold Weekend To Close Out With More Snow

Brad Leave a comment

The cold front that pushed through last night will usher in a reinforcing shot of Arctic air which will drop our temperatures back below-normal for the next few days. The weather will remain fairly benign until Sunday when a potent inverted trough low-pressure system will bring snow to Southern Manitoba.

Friday & Saturday

Friday
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Mostly cloudy with light scattered flurries. Clearing overnight.
-13°C / -21°C
Saturday
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Sunny.
-11°C / -21°C

We’ll see mainly cloudy skies today with some light flurries scattered through the Red River Valley. Temperatures will be quite cool with a brisk northerly wind limiting our daytime high to only –13°C as it ushers Arctic air into Southern Manitoba. Skies will slowly clear out overnight as we head to an overnight low near –21°C. On Saturday we’ll see sunny skies with light winds and a high near –11°C. Temperatures will drop back to around –21°C again Saturday night under clear skies.

Sunday

Sunday will be the most active weather day we’ve had in Southern Manitoba in a while. An inverted trough will push into Southern Manitoba through the morning hours with snow beginning over SW Manitoba through the morning and moving into the Red River Valley by the evening. Right now it looks like this system will develop in a somewhat complex manner; a low pressure system will push out of Montana and intensify as it moves into South Dakota and taps into moister air over the Central Plains. This moisture will surge northwards ahead of the low, which will be rapidly evolving as it interacts with a strengthening shortwave travelling along the MB/ND border. The low will rapidly develop a sharp inverted trough and feed plenty of moisture into it. This is not dissimilar to the setup earlier this month that brought 2 feet of snow to some communities in the SW Red River Valley, but at this point it does not look like this system will be nearly as potent.

Liquid-equivalent precipitation amounts from the GDPS from Sunday morning to Monday morning.

Liquid-equivalent precipitation amounts from the GDPS for Sunday morning through Monday morning.

At the moment, it appears that most communities near the International Border (from Melita all the way to Emerson) will see between 10–20cm of snow; regions near the western escarpment of the Red River Valley may see an additional 5–10cm above that figure due to localized upslope enhancement from the easterly/northeasterly winds that will set up with this inverted trough. Further north in communities along the Trans-Canada Highway (Brandon, Portage la Prairie, Winnipeg), snowfall accumulations will be quite a bit less. Currently it looks like around 5–10cm can be expected, diminishing to closer to 5cm in the Whiteshell. This is simply a first guess, though; this system may end up developing in a completely different manner should only a few small things change. I’ve erred on the side of caution, giving what I think is a “worst case” scenario. Snowfall amounts could very well be less than mentioned here; we’ll provide an update tomorrow in the comments below updating what this system looks like it’s doing, along with a snowfall forecast map.

Next Week

This system will push off into Ontario on Monday and we’ll begin a slow trek back towards seasonal temperatures through the rest of the week. With warmer air trying to push into the province, it looks like we’ll have several chances to see more snow with as a more unsettled pattern develops.

More Cold Weather on the Way

Brad Leave a comment

While you may have fond memories of the 20°C weather we were having at this time last year, spring-like weather looks to be a long way off as a low pressure system deepening in Alberta will usher below-seasonal temperatures into the Prairies in it’s wake as it moves through our region tomorrow.

12hr. precipitation totals from the GDPS

12hr. precipitation accumulations from the GDPS for Thursday night as snow moves across southern Manitoba.
Wednesday

Increasing cloudiness.
-7°C / -10°C

The warm front associated with this system will move towards the Red River Valley this afternoon bringing with it increasing cloud cover and a breezy southerly wind. By late this afternoon the Red River Valley will be mainly cloudy with a southerly wind at around 30km/h and we’ll have climbed to a temperature of about –7°C. There will be a slight chance for some light flurries in Winnipeg and areas south this evening with the passage of the warm front, but meager moisture along the front combined with very dry air being advected into the RRV from the ridge of high pressure to our east will likely mean that most of the snow developed by the front will evaporate in the dry air before it hits the ground. If any organized snow does manage to develop, amounts will be insignificant as the snow will be light and short-lived. Temperatures will only drop to about –10°C under cloudy skies tonight as we sit in the warm sector before the cold front sweeps through.

Thursday & Friday

Thursday

Increasing cloud with evening flurries. 1-4cm expected.
-5°C / -15°C
Friday

Clearing.
-12°C / -22°C

Skies will briefly clear out on Thursday morning before more clouds move in midday in advance of the approaching cold front. Temperatures will climb up to around –5°C with light winds. The cold front associated with this system will begin to push it’s way through the Red River Valley in the evening and will bring some snow along with it. The snow should start a little later on Thursday evening and let up early Friday morning. Accumulations will not be very significant with only 2–4cm expected to be maximum amounts across the RRV. There’s a slight chance that some areas close to the U.S. border such as Morden, Gretna, Altona and Emerson, may see closer to 5cm as the bulk of the snowfall associated with this front is expected to fall in North Dakota and the slightly higher amounts may brush the extreme southern Red River Valley.

On Friday, we’ll see clearing skies as an Arctic ridge begins working into the Prairies. Temperatures will be quite cool for mid-March with daytime highs only hitting –12 or –13*°C, a whole 6–8°C below seasonal.

Weekend at a Glance

Saturday will be a near carbon-copy of Friday with sunny skies and a cool daytime high of around –11°C. Current indications for Sunday show a strong potential for a potent Alberta Clipper system to race along the U.S. border and spread snow through the Red River Valley by Sunday afternoon. It’s fairly early to focus too much on details, but forecasts currently indicate that 5–10cm of snow is quite possible from Winnipeg & the Trans-Canada highway south throug the RRV to the border. We’ll have more details on this system in our post later this week.

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!

Cool Weather Returns

Brad Leave a comment

After enjoying a couple days of above-normal temperatures, a powerful low pressure system backing into Hudson Bay will drive a cold front southwards across Southern Manitoba today, bringing with it cooler weather.

850mb Temperature Analysis valid 15Z this morning

850mb GEM-Reg Temperature Analysis valid 15Z this morning.

The cold front will sweep through Southern Manitoba late this morning, with winds picking up from the north and increasing to 30-40km/h. Scattered showers will develop along the front as it pushes through the interlake, so most regions in the Red River Valley have a chance of seeing some rain later this morning. It won’t last long, though, and cooler air will stream in on the backside limiting our daytime high in Winnipeg to around 11°C. Skies will clear quickly tonight as an Arctic ridge builds in and helps our overnight low drop to -4°C.

The aforementioned low backing into Hudson Bay will become captured today and will block the eastwards advancement of the Arctic ridge which means, unfortunately, that we’ll be under the influence of the ridge and its outflow for the next few days. Thursday will see sunny skies with a daytime high of only around 9°C, and Friday will be much of the same with a high just a couple degrees warmer. By Saturday it looks like the ridge will start to move off and although the day will still be cool, a southerly flow will begin to bring warmer weather back to our region.