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.

Mild Start to Week Turns Unpleasant

Winnipeg will enjoy two mild days before what may be a significant winter storm moves into the province.

Winnipeg will enjoy seasonable warmth over the next couple days. An upper level ridge moving across the region will usher in southerly winds and warmer weather. Both today and tomorrow will see highs climb towards 20°C with southerly winds of 20 to 30 km/h. The city should see plenty of sunshine both days and seasonably mild overnight lows.

Seasonably mild temperatures will be in place over southern Manitoba on Tuesday while a sharp cold front pushes towards the region.
Seasonably mild temperatures will be in place over southern Manitoba on Tuesday while a sharp cold front pushes towards the region.

Unfortunately, a significant change in the weather is on the way for Wednesday. A potent low pressure system tracking through the Northwest Territories will combine with a deepening long-wave trough to send a cold front surging southeastwards across the Prairies. It will push into southern Manitoba on Wednesday, bringing much cooler temperatures and cloudy skies. Winds will strengthen to 30 gusting 50 km/h out of the north and the entire region will see a chance of showers.

While the Red River Valley may see rain showers on Wednesday, snow will likely push into southwestern Manitoba and the Interlake region.
While the Red River Valley may see rain showers on Wednesday, snow will likely push into southwestern Manitoba and the Interlake region.

The precipitation will organize on Wednesday night with heavier bands lifting northeastwards out of the Dakotas. There’s some uncertainty right now, but it’s possible that the rain mixes or changes over to snow sometime Wednesday night.

Long Range Outlook

Before anything else: there is still significant uncertainty with how the weather will develop later this week. With that said, southern Manitoba may see a multi-day winter storm on Thursday through Saturday. A potent Colorado Low will begin lifting northeastwards on Thursday, spreading moderate to heavy precipitation into the region. While this happens, northerly winds will strengthen and sustain a feed of cold Arctic air into the region. As the low reaches Lake of the Woods on Friday, it is forecast to stall out for 24 to 48 hours. This will result in bands of precipitation back into southern Manitoba, gradually changing to snow.

Exactly how much precipitation the region sees and what it falls at is uncertain; there’s a lot of ways this forecast can change between now and then. If this ends up on the snowier side, it could end up being a fairly major snowfall with at least 20 to 30 cm of the white stuff. Persistent rainfall may reduce snowfall amounts in some areas. But more rain isn’t exactly a desirable thing for a region whose rivers are already swollen with excess rainfall over the past month. This system could easily produce another 25 to 50 mm over the region which, if falling as rain, would quickly find its way into the river and aggravate overland flooding issues that exist in areas of the province.

We’ll be keeping an eye on this system as it develops and have more details in our Wednesday morning forecast.

Today’s seasonal daytime high in Winnipeg is 13°C while the seasonal overnight low is +2°C.

Winnipeg Set For A Mild Weekend, But A Big Cool Down Looms on Horizon

The mild weather Winnipeg has seen lately will last for a few more days, but a low pressure system that tracks across the northern United States on Sunday night will usher in a major pattern change which will allow Arctic air to spill southwards across the Prairies, bringing significantly colder temperatures to southern Manitoba.

Warm, unremarkable weather is on tap for Winnipeg today and tomorrow as a slack flow remains over the region with just a few very weak upper-level disturbances moving through. A weak upper-level disturbance moving into the region will bring increasing cloudiness today as temperatures head to a high near +1°C. No precipitation is expected and winds will remain light. Temperatures will dip down to a low near -7°C tonight with the clouds clearing out by Saturday morning.

Winnipeg will see partly cloudy skies on Saturday with temperatures rebounding to a high near 0°C with light southerly winds. Temperatures will then dip to a low near -6°C on Saturday night with increasing cloudiness.

Everything begins to change on Sunday as a low pressure system develops across the northern Plains of the United States. There’s still a fair amount of uncertainty associated with this low; some models want to keep it relatively progressive and move it through South Dakota, while others develop a more potent Colorado Low that lifts northeastwards towards Thunder Bay. Either way, it should bring mainly cloudy skies to the region on Sunday with a chance for snow moving in on Sunday night. Given the significant uncertainty with this system, an update on what to expect will be posted sometime Saturday evening or Sunday morning.

Long Range Outlook

Without question, the biggest aspect of the long-range forecast is the dramatic cool-down that will occur next week.

By Tuesday morning a much cooler air mass is forecast to be in place over the province

As Sunday’s low pushes eastwards, a large upper-level ridge will build over British Columbia, remaining anchored over the Rockies. A large upper-level trough will develop over eastern North America, bolstered by the incoming low pressure system from the Northern Plains.

This pattern will result in a steady northwesterly flow over the Prairies, setting up an Arctic pipeline that will usher much colder air southwards into the Prairies. It appears that by mid-week, daytime highs in Winnipeg may fall into the mid-minus teens. Another way: by the middle of next week, Winnipeg’s daytime highs may fall to what the seasonal overnight lows are for this time of year.

So, enjoy the mild weather while it lasts, by this time next week it will be a whole lot colder than it is now!

Winnipeg’s seasonal daytime high is currently -7°C while the seasonal overnight low is -16°C.

Unseasonal Warmth Will Challenge Numerous Records

Winnipeg will see the peak warmth of the current weather system move in today with temperatures climbing well above the freezing mark. The unseasonable warmth will challenge several record types: record highs, record high minimums, record high dew points, and record high minimum dew points.

Everything ending in °C will be the highlight over the coming days as even more warm air floods into the region. Today’s high will reach around 4°C, while tomorrow’s and Sunday’s highs will be near 3°C. Overnight lows will remain very mild as well, with lows near 0°C tonight, -5°C tomorrow night and +1°C on Sunday night.

Winnipeg, MB Temperature & Dewpoint Records for February 17-19
Date Record Type Current Record
February 17 High Temperature 5.4°C (1981)
High Minimum Temperature 0.8 (1998)
High Dewpoint 2.0°C (1981)
High Minimum Dewpoint -0.6°C (1998)
February 18 High Temperature 3.9°C (1954)
High Minimum Temperature -0.2°C (1998)
High Dewpoint 0.6°C (1954)
High Minimum Dewpoint -1.3°C (1998)
February 19 High Temperature 5.6°C (1930)
High Minimum Temperature 0.2°C (2016)
High Dewpoint 0.6°C (1954)
High Minimum Dewpoint -0.5°C (1981)

These temperatures will challenge many of the records listed above. For daytime highs, it’s important to note that there will likely be significant variability around the city. The official records are for the official Environment & Climate Change Canada observing site located at the Winnipeg airport, which tends to be colder than much of the city during warm spells at this time of year. Throughout the city, temperatures could be anywhere from 2-4°C higher than what’s reported at the ECCC site.

The GDPS is forecasting temperatures up to 12-14°C above normal over the coming few days in Winnipeg.

Skies will see variable cloudiness over the next few days, but we’ll see no real threat of precipitation aside from a very low chance of a light rain shower this evening.

Winds will strength out of the southwest today to around 25-35 km/h with some gustiness, particularly near the western escarpment of the Red River Valley. These winds will continue overnight and then gradually taper off on Saturday. The wind will then swing around to the east/southeast on Saturday night and begin strengthening on Sunday to 20-30 km/h ahead of the next system.

Long Range

The beginning of next week will bring a Colorado Low that poses the threat for significant impact on the region, however it’s difficult to pin down much of a forecast at this point as solutions for this disturbance vary dramatically, with some models dragging the precipitation of the low up the Saskatchewan/Manitoba border and others shunting it well off to the east over Lake Superior.

What we can say is that there will be a Colorado Low that will threaten the region on Monday, potentially into Tuesday. This system will be bringing an abnormally high amount of moisture with it, and with the mild temperatures, that means that any precipitation from it would fall as rain. Forecast amounts have varied, but in general it seems like this system will produce a swath that receives 10-20mm of rain. Whether or not that falls in the Red River Valley will yet to be seen.

That much rainfall would be very abnormal for this time of year. Current rainfall records for this general time of year are:

Winnipeg, MB Rainfall Records for February 19-21
Date Record Type Current Record
February 19 Rainfall 1.0mm (1997)
February 20 Rainfall 0.3mm (1965)
February 21 Rainfall 5.8mm (1877)

The potential to over double the current record rainfall amount, all the while still having frozen ground with high water content and a fair amount of snow would likely introduce a risk for overland flooding.1 In North Dakota, the NWS has issued hazardous weather outlooks regarding this system for the potential for minor water level rises in low-lying areas and for area rivers. In the end, though, there’s still a lot of uncertainty in where exactly this system will track, so we’ll be keeping an eye on things as it develops.

Otherwise, temperatures will finally begin to cool back towards normal behind this system, but it continues to appear like southern Manitoba will be near the primary storm track and see more frequently unsettled weather through the remainder of next week.

Winnipeg’s seasonal daytime high is currently -8°C while the seasonal overnight low is -18°C.

  1. While I do have training in meteorology, this sort of issue is more of a hydrological challenge. I’m not formally trained in hydrology, but the fields are closely related and I do have some familiarity with it. That said, as it gets closer, monitor the news for any statements from the Province of Manitoba regarding the flooding threat.