Tag: Snow

Cold Start to the Week

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This week will start off feeling a lot more like winter, as temperatures drop well below normal.

A high pressure system will bring cold conditions to Southern Manitoba on Monday

A high pressure system will bring cold conditions to Southern Manitoba on Monday

Temperatures this morning will be more like those you’d expect in late January, not late November. This morning’s cold temperatures will moderate somewhat by afternoon, with highs in the mid minus teens expected – not exactly November weather! Luckily some cloud cloud should move in during the afternoon hours, allowing Monday night to be significantly warmer than Monday morning. In fact temperatures may rise a bit on Monday night, up into the -6 to -10C range, in association with a weak low pressure system passing through. This low will bring a few flurries to Southern Manitoba overnight, with accumulations of no more than a centimetre or two expected. Unfortunately, another high pressure system will build in behind this passing low, bringing colder temperatures again for the daytime hours of Tuesday. Temperatures will begin falling back into the minus teens on Tuesday morning as cooler air spills in from the north-west. Tuesday night will be another cold one, with lows back down around the -20C mark. It looks like another small warm-up is on the way for Wednesday as yet another passing low pressure centre allows temperatures to climb back up into the minus single digits.

There remains some uncertainly in terms of how the late week period will play out. Models generally agree that we will stay below-normal for Thursday and Friday, but exactly how cold is not entirely clear. There have also been hints of a more active storm track setting up through Southern Manitoba from next weekend into the following week, something to watch as this week progresses.

A Mixed Bag

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We’ll see some sun, some more snow, and temperatures all over the place as we see a wild weather pattern over the next few days.

12hr. QPF for Saturday

Precipitation accumulation for Saturday, showing some snow pushing through Southern Manitoba with greatest accumulations north and east of Winnipeg.

Sunshine will dominate today as a very strong Arctic high slumps through the Prairies. This high pressure system is a result of cold Arctic air pushing southwards behind a cold front that passed through yesterday. This will limit daytime highs today in the Red River Valley to only about -12°C. Temperatures will plummet towards -20°C tomorrow night as the ridge pushes through Southern Manitoba and breaks up remnant cloud left behind.

More cloud will begin pushing in late overnight into Saturday morning as another system tracks through the Northern Prairies. This system will warm things up a bit for us, bringing our daytime high on Saturday to a comparatively balmy temperature climbing just over -5°C. To go with those warmer temperatures will be some light snow with accumulations only around 2cm for much of the Red River Valley, including Winnipeg.

This system moves out on Saturday night, and we’ll move into a slightly more stable pattern. Sunday will likely be a mix of sun and cloud as we deal with a little bit of cloud left behind from Saturday’s system, with a high near -12°C again. As we head into next week, things look fairly steady with overnight lows near -15°C and daytime highs starting in the high minus teens and climbing into the low minus single digits.

A Return to Winter

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Colder air is set to return by the end of the week as a low pressure system ushers in Arctic air as winds shift to the northwest behind it.

GFS Sounding for 06Z Thursday

A sounding for 06Z Thursday (midnight-ish tonight) from the GFS model depicting an above-freezing level.

Before the cold weather returns we’ll have one more pleasant day. Although skies will be cloudy today, we’ll see temperatures once again climbing above 0°C through the Red River Valley with a light southerly flow. Conditions will begin to degrade overnight as a low pressure system pushes into Southern Manitoba.

The first threat with this system will be the potential for freezing rain tonight. As the sounding1 above shows, an AFL (Above Freezing Level) with sub-zero surface temperatures will be in place through much of the overnight period before eroding early Thursday morning. The saving grace for the Red River Valley could be that most of the precipitation looks to push north of the valley through the Interlake. If, however, any precipitation manages to wander through the RRV overnight, then there’s certainly a decent chance it’ll fall as freezing rain. Cooler air begins pushing in at all levels early Thursday as we move to the back side of this system and winds switch to the northwest.

Winds will strengthen out of the northwest on Thursday to 40km/h with gusts towards 60km/h as a band of snow slumps southwards with the cold front. At this point, it looks like snow will push into the Red River Valley mid-morning and last until the early evening (6-8PM). Snowfall accumulations will likely be around 5cm. Temperatures will start near -5°C tomorrow morning and fall to -8 or -9°C by the evening. We’ll head to an overnight low of around -15°C tomorrow night.

Sunny skies should dominate Friday and Saturday with highs near -10°C. A weak disturbance looks to bring a chance of light snow to the Red River Valley again on Sunday.

  1. A “sounding” is a way of plotting how the temperature and dewpoint change with height. The sounding is for a single location and plots the temperature/dewpoint with height in pressure coordinates as the vertical axis. ↩

Major Winter Storm Ushers in Winter

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A major Colorado low will bring an end to fall and transform our dry, dusty landscape into a winter wonderland this weekend. This storm will have major impacts on Southern Manitoba with heavy snow producing rapid accumulations and moderate strength winds producing low visibilities and drifting snow.

Satellite Image from 9PM Yesterday

Satellite image from 9PM last night showing location of the main low (marked by the large L) and the area of snow already developed out ahead of it.

Snow will push into southwestern Manitoba this evening as a band of snow that has produced 10-20cm of snow in Southern Saskatchewan spreads eastwards into Manitoba. This snow will intensify over the SW portion of the province overnight and slowly spread eastwards. By tomorrow morning, snow should have pushed across all of southern Manitoba, with light snow falling over the RRV and Whiteshell.

On Saturday, the main low centre associated with this system will push into Minnesota, and things really start to fire up. A surge of moisture will wrap around the north side of this system back into Southern Manitoba resulting in heavy snowfall over the Red River Valley and Whiteshell.

Total QPF

Total QPF amounts (liquid equivalent precipitation) by Sunday morning.

The GEM-GLB model is beginning to have a fairly decent handle on things, however it’s track is likely a little too far south. Amounts seem fairly believable, though, which means widespread accumulations of 15-20cm of snow for all areas south of the Trans-Canada Highway. An axis of heavier snow will exist, likely from near the Pilot Mound region extending NE through (or just south of) Winnipeg and towards Bisset, where amounts will likely end up closer to 20-25cm.

There’s some indications that convective banded precipitation may develop as well; should this happen, there would likely be areas in the Red River Valley (too hard to say exactly where at this time) that could potentially see 30cm+ of snow (that’s a foot if you prefer those imperial measurements).

Winds will remain moderate, only around 30km/h with gusts to 50km/h, however with the intensity of the snowfall, there will likely be periods of near-zero visibility. It’s also very likely that roads will quickly become snow- and ice-covered, with some drifts developing over highways in open areas. Travel will be extremely treacherous on Saturday, and highway conditions will likely not improve until crews have been able to get out and start clearing things on Sunday.

If you have travel plans on Manitoba highways for this weekend, it is important to note that 10-20cm of snow will fall across much of Southern Saskatchewan today. Through yesterday and by the end of today, up to 2 feet of snow will have fallen through central and eastern Montana, and conditions will be equally poor in North Dakota today and tomorrow. This storm will be arriving a little later in NW Ontario, with the precipitation (likely with an area of freezing rain) arriving Saturday morning instead of Friday evening. More or less, unless you’re driving north, you’ll likely be hitting challenging road conditions no matter where you’re headed this weekend. If you do need to travel in a winter storm, make sure you carry a winter survival kit in your vehicle.