Cool Conditions Ahead for Winnipeg

The broad pattern change that began this week will establish itself by the weekend, bringing a prolonged period of seasonably cool conditions to the region.

RDPS 2m Temperature Forecast valid 21Z Saturday October 28, 2023
Seasonably cool temperatures will flood the Prairies this weekend with daytime highs below freezing in most places.

The weather pattern across southern Manitoba will be dominated by a slow-moving upper trough extending from an Arctic vortex over Canada’s eastern Arctic. This will ensure a pipeline of cooler air sourced from the Arctic sits pointed at the region right into next week, delivery seasonably cool temperatures to the area.

It will be mainly cloudy in Winnipeg today with some morning snow tapering off as a disturbance tracks off the the east. In its wake, northerly winds up to 30 gusting 50 km/h will pump cooler air southwards, supporting bands of lake-effect flurries off of both Lake Manitoba and Lake Winnipeg. This will result in a few flurries lingering through the day, as well as some more concentrated bands of snow in the lee of the lakes. Temperatures will climb to around the freezing mark, then dip down into the -5 to -10 °C overnight as skies clear.

Sunnier skies will return for Saturday with highs in the -5 to 0 °C range with southwesterly winds in the 20 to 30 km/h range. A bit of cloud will push back into the region on Saturday night, but lows will still dip down close to -10 °C.

On Sunday, there will likely be a bit more cloud around with just a slight chance of some flurries. Temperatures will again climb into the -5 to 0 °C range with westerly winds again near 20 km/h.

Long Range Outlook

Highs will likely bounce back to the freezing mark on Monday with a passing disturbance that will also bring some light snow to the region, then cooler weather returns for the rest of the week with highs in the -5 to 0 °C range and overnight lows closer to -10 °C.

For Halloween, it’s looking like it will be a partly cloudy day with a cool high near -5 °C. By the time kids start heading out in the evening, temperatures will likely have dipped into the -5 to -10 °C range with southwest winds near 15 km/h.

Today’s seasonal daytime high in Winnipeg is 6 °C while the seasonal overnight low is -3 °C.

Snow Gives Way to Sunny but Cool Weekend

Snow will come to an end over the region today as the storm that’s been stalled over the region finally moves east. Sunnier skies will return for the weekend as a high pressure system settles over the province.

RDPS MLSP & 10m Wind Forecast valid 18Z Saturday April 22, 2023
A broad area of high pressure will settle across the eastern Prairies this weekend.

Snow continues to wrap into southern Manitoba this morning, but conditions will improve through the day. As the low responsible for our weather continues to trundle eastwards into Ontario, snow gradually weaken and taper off over southern Manitoba. It will be a bit of a slick and slippery morning as temperatures dip below zero and combine with fairly strong northerly winds near 50 gusting 70 km/h.

Temperatures will rebound to a high of only around +2 °C.

Skies will clear out tonight as winds ease to around 20 km/h. Temperatures will dip to a low in the mid-minus single digits.

For th weekend, a ridge of high pressure will build into the region and bring cool but settled conditions. Winnipeg and area will see variable cloudiness through the weekend with daytime highs in the mid- to upper-single digits. Overnight lows will likely dip into the -5 to -10 °C range.

Long Range Outlook

Next week will start off with quieter weather as temperatures gradually move towards more seasonal values. Some rain may be possible across the region late next week.

Today’s seasonal daytime high in Winnipeg is 13 °C while the seasonal overnight low is 0 °C.

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.

Spring Storm to be Followed by Much Warmer Weather

A Colorado Low is on the way to Southern Manitoba and will bring snow and blowing snow to the region beginning Tuesday night. This storm will exit the region on Thursday, and after a couple cool days much warmer spring weather will move into the province.

Weather alert map valid 0827Z Tuesday April 4, 2023
Winter storm warnings are out across southern Manitoba (red on the Canadian side of the border) with blizzard warnings across much of the Northern Plains of the United States (red south of the international border) for a potent spring storm moving into the region. Image valid at 8:30 AM Tuesday March 4, 2023.

A Colorado Low is organizing south of the border that will bring a blast of winter weather to parts of southern Manitoba. It has already begun to spread a band of snow through South Dakota that will lift north-northeast through the day today.

In Southern Manitoba, the snow will approach the southern border by evening, then spread into the province overnight. Light snow will fall across southwest Manitoba, with heavier snow pushing into the Red River Valley and southeastern corner of the province. The Trans-Canada Highway corridor in the RRV will likely receive 5–10 cm of snow by Wednesday morning with higher amounts of 10–20 cm to the south and southeast.

Snow will continue across the Red River Valley and east on Wednesday with another 5 to 10 cm likely in most regions. The snow will finally begin to taper off on Wednesday night. By the time all is said and done, much of southern Manitoba will receive 15 to 25 cm of snow; amounts will drop off quickly west and north of a line running roughly from Pilot Mound to Berens River. The heaviest amounts could reach into the 30 to 40 cm range with the highest risk for that much snow focused in two locations: Sprague and the southwest Red River Valley, particularly in the areas closer to the western escarpment.

RDPS Total Accumulated Snowfall Forecast (10:1 SLR) valid 12Z Thursday April 6, 2023
Much of southern Manitoba will see notable snowfall accumulation as the region is clipped by a Colorado Low Tuesday night through Wednesday.

In addition to the snow, moderate northwesterly winds will develop on Wednesday, bringing areas of blowing snow to the Red River Valley. In combination with the moderate falling snow, expect poor travel conditions across the region, including southward into the United States, Tuesday night through Thursday.

Please refer to the Meteorological Service of Canada for the latest weather alerts for Manitoba.

Temperatures will run seasonably cool through the storm with highs in the -5 to 0 °C range over the next few days. Lows will generally sit in the -5 to -10 °C range, except for Thursday night where clear skies will combine with the fresh snow to send lows into the mid-minus teens.

Long Range Outlook

Probably just as notable as all the snow coming over the next couple days will be the forecast for the weekend. As the Colorado Low pushes northwards, it will dislodge the Polar Vortex and send it further north, finally loosening its influence over the eastern Prairies. A more zonal flow aloft will develop over the region, and much warmer Pacific air will begin to sweep across the Prairies this weekend.

The extensive snow pack over the region will limit daytime highs into the low to mid-single digits. If the ground were completely bare and skies were sunny, daytime highs in the mid-teens could be possible Sunday into Monday; alas. But in addition to temperatures climbing above freezing, this push of warm air will also likely send dew point values above 0 °C as well.

Dew point values rising above freezing greatly enhance how quickly snow can melt, and although the warmer weather will be welcome, it may result in a lot of melting from Saturday through Wednesday. Given the pre-existing concern in Manitoba’s flood forecast, this could result in a higher flood risk for some areas. Be sure to watch for updated Manitoba Flood Forecasts and Reports if you are concerned that you may be impacted by a quick melt.

Today’s seasonal daytime high in Winnipeg is 7 °C while the seasonal overnight low is -4 °C.