Slow-Moving Disturbance to Bring Spring Storm to Southern Manitoba

A slow-moving upper-level disturbance will bring cooler temperatures and plenty of snow to parts of southern Manitoba this week.

GDPS 500mb Height and Wind Forecast valid 00Z Thursday April 20, 2023
A potent, slow-moving upper low will bring a multi-day snowfall event to southern Manitoba.

Winnipeg and area will see a relatively pleasant spring day today as a ridge of high pressure continues to sit over the region. Temperatures will climb up to around the 10 °C mark this afternoon with increasing easterly winds towards evening.

A large upper-level disturbance will begin working into the region tonight. It will spread precipitation through Saskatchewan today, reaching SW Manitoba by the evening. This system may start as a wintery mix in Saskatchewan today, but will trend towards primarily a snow-maker as it moves into Manitoba.

This system will produce significant amounts of snowfall over southeast Saskatchewan into parts of SW and Parkland Manitoba. By Wednesday morning, 5–10 cm of snow will have likely fallen across those regions with another 10–20 cm through the day Wednesday. On Wednesday night, another 5–10 cm will fall across those areas, with higher possible along the escarpment west of Lake Manitoba and Lake Winnipegosis. The snow will gradually come to an end in those areas on Thursday, with accumulations ranging from a couple centimetres to as much as another 5–10 cm.

Further east in Winnipeg and much of the Red River Valley, snow should push through the area in multiple waves. Some light snow or rain showers are possible later today, but copious amounts of dry air near the surface will likely evaporate much of that activity before it reaches the ground.

The first organized wave of snow will push into the region on Wednesday morning, moving northwards through the day. This will drop 2–5 cm across much of the Red River Valley on Wednesday, though amounts may increase quickly close to the western escarpment. Some periods of light snow are possible on Thursday, though much of the organized activity will likely remain to the west.

A more organized band of accumulating snow will push towards Winnipeg on Thursday evening as another wave of moisture wraps into the system impacting the area. This could bring Winnipeg’s heaviest snowfall of the event with the potential of anywhere from 5 to 15 cm of snow.

Throughout this entire disturbance, moderate easterly winds will slowly shift northerly over the course of the week, and temperatures will struggle to climb only  at most to a few degrees above freezing. There is a slight chance that precipitation could briefly change over to rain, particularly for areas south of Winnipeg, if a bit of warmer air can wrap into this system at times.

Keep alert for updated watches or warnings from the Meteorological Service of Canada.

The last note for this system is that in many areas, snow will fall with temperatures close to 0 °C. As a result, some may melt and much of the snow will be relatively heavy and prone to compaction. This may make measurable snow on the ground at the end of the event less than what actually fell.

Long Range Outlook

This system will finally begin to clear out of the region on Friday, followed by a couple days of seasonably cool temperatures.

A return to seasonal warmth with highs in the low teens should build into the region early next week.

Today’s seasonal daytime high in Winnipeg is 11 °C while the seasonal overnight low is -1 °C.

Major Spring Storm On The Way For Southern Manitoba

The most significant spring blizzard in decades is bearing down on southern Manitoba, but there’s nuance in the details. What follows is the best interpretation of the upcoming weather we can discern as of the time of writing. The forecast for this system may change on short notice, so be sure to keep alert of any updated forecasts or warnings from official sources.

GDPS Total Snowfall Forecast valid 00Z Saturday April 16, 2022
The Canadian GDPS model has slightly less snow than many of its peers, but shows well the very large area that will likely see 20–40 cm of snow. Other forecast models show accumulations over 25% higher than these values.

A complex storm system will bring a major spring blizzard to southern Manitoba beginning later today. While the broad strokes of this system have been quite clear for several days now — a testament to improvements in medium-range weather modelling over the past decade — there are many nuances to this system that will add layers of complexity to the forecast.

A pair of low pressure systems have merged overnight and now exist as a single potent low centred over western Nebraska and Colorado. This system is supported by two distinct features: an upper low over Iowa and a digging upper trough over Utah and Colorado. These two upper features and their evolution will guide the development of this system over the next 36 hours.

As this system pushes eastwards today, it will split into two surface lows: one that lifts northwards through the Dakotas through the day, and another that lingers in Colorado for a while longer before ejecting northeastwards into Minnesota. The northern low will be supported by the upper low, while the southern low will move along with the upper trough and strong frontal wave.

The first wave of snow will move into southern Manitoba this evening, supported by the northern low pressure system. This snow will likely be quite heavy with snowfall rates reaching as high as 3–5 cm/hr. This first shot of snow will lift from North Dakota into SE Saskatchewan and SW Manitoba, then spread eastwards across the Red River Valley and into NW Ontario. By the end of Wednesday, it’s likely that 20–40 cm of snow will have fallen over the southwestern corner of the province and the western escarpment/Riding Mountains, and 10–20 cm of snow in the Red River Valley and southeast corner of the province.

As the day progresses on Wednesday, the precipitation lifts northwards as the northerly surface low stalls out near the MB/ND/MN borders. It looks quite likely that this system’s dry slot will spread into southern Manitoba, bringing an end to most of the snow over the Red River Valley and southeastern Manitoba. If this happens, the region would see a reprieve from the snow later Wednesday through the night, but with a decent chance of [freezing] drizzle or few flurries through that period. The snow will continue elsewhere in Manitoba, albeit comparatively lightly with general accumulations overnight of 5–10 cm. Terrain features will continue to see enhanced accumulations with 10–20 cm possible, particularly closer to Lake Manitoba and the Riding Mountains.

On Thursday, the Colorado Low will become dominant in NW Ontario, producing heavy snow that will spread westwards across the Interlake into western Manitoba through the day. Light to moderate snow will spread back through the Red River Valley for Thursday. The stalled surface low in Manitoba will collapse as the Ontario low strengthens, and the strongest winds will shift eastwards into the Red River Valley with sustained northerlies of 50–60 km/h. Close to 5 more centimetres of snow is likely for Winnipeg on Thursday.

The snow will begin to ease on Thursday night, then clear out of the region through Friday.

RDPS 10m Wind Forecast valid 15Z Wednesday April 13, 2022
This storm will bring moderate to strong north-northeast winds to parts of southeastern Saskatchewan and southern Manitoba on Wednesday morning. The winds will ease slightly and shift into the Red River Valley on Thursday.

Regarding the wind and blowing snow, the stalling of the low near the MB/ND/MN border and timing of the NW Ontario low takeover will result in full-fledged blizzard conditions being most likely in SE Saskatchewan into SW Manitoba. Lighter winds are likely in the Red River Valley, and the peak forecast winds for this system have subdued slightly. That said, especially in the first wave, white-out conditions will be possible in heavy snow.

So, by the time the snow tapers off on Friday, it still look likely that 30 to 50 cm of snow will fall widespread across southern Manitoba. It will be a fairly persistent event from areas in SE Saskatchewan through southwest and western Manitoba as well across the Interlake. It looks like the situation in the Red River Valley will be different though, with multiple waves of snow. Winnipeg and area will likely see a wave of very heavy snow on Wednesday morning taper off later in the day with as much as 15–25 cm possible. Snow will likely ease for the city Wednesday evening/overnight with a chance of [freezing] drizzle. The wind will pick up on Thursday as more snow moves back into the region; the Winnipeg area will likely could see as much as 5–10 cm of snow.

Lighter amounts will fall to the south, but a heavier band of snow the north will give 10+ centimetres to the Interlake and other parts of central Manitoba.

The snow, wind, and blowing snow will begin to ease Thursday night, with conditions continuing to improve on Friday. For Winnipeg, this means that about half of the expected snow will likely fall on Wednesday alone, with the other half or so coming over the following 24–36 hours as a separate wave of snow. It will still amount to quite a bit, but it won’t be the 3-day raging blizzard like it looked like it could be even a day ago.

Temperatures will hover just above freezing today and tomorrow, then fall below freezing on Thursday.

Long Range Outlook

Cooler temperatures will stick around for the weekend with sub-freezing highs and seasonably cool lows. It should be a relatively quiet period for several days after this event, giving plenty of time to clean up after this storm.

Today’s seasonal daytime high in Winnipeg is 9 °C while the seasonal overnight low is -3 °C.

Major Winter Storm Hammers Southern Manitoba

A Colorado Low is bringing a major early-season winter storm to southern Manitoba that ranges from rain to a crippling blizzard.

Because the storm is ongoing and long-lasting, we are not issuing a standard forecast today. This is a complex and dynamic system that requires constant monitoring as the snow/rain line wiggles around the region. We strongly encourage you check your local weather forecast from ECCC and the weather warnings in your area.

As a general overview, a Colorado Low will gradually move into southeastern Manitoba today. Waves of rain will spread westwards, transitioning into moderate to heavy snow over the Red River Valley and areas west. Storm total snowfall will range from a trace all the way up to in excess of 50 cm. The most snow will fall in upslope areas of the Turtle Mountains, Riding Mountains, and the western escarpment of the Red River Valley. The snow that is falling will be wet, heavy snow, resulting in significant snow loading on trees and infrastructure.

Complicating matters will be strong north-northwest winds with widespread gusts in the 70 to 90 km/h range. These strong winds, combined with the heavy snow, will produce poor visibilities and an elevated risk of damage to trees an infrastructure. Over 23,000 people were without power on Thursday evening and the widespread power outages will likely continue today as well.

Heavy snow will continue over southern Manitoba today with the hardest hit areas extending from the western Red River Valley region southwards into eastern North Dakota.

The storm will gradually ease across the region on Saturday, leaving just a few flurries or showers for Sunday.

Today’s seasonal daytime high in Winnipeg is 12°C while the seasonal overnight low is +1°C.

Major Winter Storm Set to Hit Southern Manitoba, North Dakota

A potent Colorado low will bring the first blast of winter to southern Manitoba in the form of a high-impact storm.

A developing Colorado Low will spread several waves of precipitation across southern Manitoba over the next few days. It all begins later today as light rain moves into the Red River Valley from the west.1 The rain will weaken overnight, but the next wave of precipitation will surge northwards early Thursday. This will fall as rain over SE Manitoba and change to snow across the Red River Valley. For many areas, it likely means a winter mix through the day.

Forecast precipitation amounts are high, with 15 to 25 mm forecast for the region. Any areas that see more of this as snow than rain could end up with a good 10 to 15 cm of wet, heavy snow by the end of the day. In Winnipeg, it looks likely that the city will see a mix of rain and snow through much of the day, changing to snow at night.

Another wave of precipitation will move through on Friday, bringing more rain and snow to the region. Another 15 to 30 mm is possible Thursday night through Friday, bringing storm-total precipitation into the 30 to 50 mm range.

Regardless of what form it takes, a lot more water is on the way for southern Manitoba.
Regardless of what form it takes, a lot more water is on the way for southern Manitoba.

Where exactly the transition from snow to rain occurs will need to be determined as the event itself develops, but we feel this is the most likely outcome. Different areas will see varying amounts of snow and snow accumulation based on where that line sets up. In the hardest hit areas, snowfall in excess of 25 cm may be possible. As mentioned before, the snow will be heavy and wet. Other areas may see upwards of 50 mm of rain. No matter how it falls, a lot more water is on the way for southern Manitoba.

Follow our twitter account for short-form updates as this system develops. If you are travelling in the coming days, know that the weather will be similarly poor across eastern North Dakota and adverse to dangerous driving conditions may develop.

In addition the precipitation, this storm will bring strong northerly winds and cool temperatures.

The cooler air will surge into the region today, sending temperatures falling to +4°C by the end of the afternoon. As the precipitation moves in tonight, temperatures should fall further to around +1°C by Thursday morning. Through the rest of the work week, temperatures will hover within a degree or two of the 0°C mark.

Winds will pick up out of the north into the 30 to 40 km/h range today, then strengthen to 40 gusting 60 km/h on Thursday. On Friday, winds may reach 50 gusting 70 km/h in some areas, especially in the lee of the lakes. In areas where these strong winds can combine with snow, visibilities will be severely restricted and the winds may produce damage add stress above and beyond the heavy loading from the wet snow.

One of the larger areas of uncertainty is on Friday. Forecast models diverge on where exactly the low centre goes, and some are bringing it relatively far west into southeastern Manitoba. If that occurred, it would be likely that Winnipeg, the eastern Red River Valley, and the southeastern corner of the province would be spared from much of the precipitation. We’ll be keeping an eye on things to see how they develop.

Long Range Outlook

A wintery mix of precipitation will likely persist through much of Saturday, tapering off to a chance of showers or flurries on Sunday. Temperatures will remain cool with highs of just 2 or 3°C and lows near +1°C. No significant precipitation is forecast into next week, although temperatures will remain well below seasonal values right into the end of the work week.

Today’s seasonal daytime high in Winnipeg is 12°C while the seasonal overnight low is 1°C.

  1. West of the Red River Valley, it will fall as snow instead.