Major Winter Storm on the Doorstep

A winter storm rapidly developing over North Dakota will spread snow, freezing rain and showers into Manitoba today, along with increasingly strong northwesterly winds. Conditions will deteriorate rapidly this morning over western Manitoba, while the Red River Valley and southeastern Manitoba see conditions deteriorate later this afternoon when temperatures begin to drop and any showers change over to snow.

Winnipeg Forecast

Warm air will be reinforced over the Red River Valley ahead of this low pressure system as east to southeasterly winds increase to around 30 gusting 50 km/h develop, keeping temperatures mild with highs near 3°C today. An area of showers will develop as the main low centre lifts into the province out of North Dakota a bit later in the morning, spreading northwards through the afternoon. Rainfall totals throughout the Red River Valley will be variable thanks to the showery nature of the rain, but in general between 2-10mm seems most likely. If some more intense showers develop, there may be a chance for isolated accumulations of 10-20 mm.

Winds will taper off late this afternoon into the early evening as the centre of the low passes through the region. As it moves off to the northeast, winds will then abruptly strengthen out of the west to northwest at 40-50 km/h with gusts up to 70 km/h. Temperatures will quickly drop below zero as some wrap-around snow moves into the Red River Valley.

While some earlier forecasts were showing significant snowfall in the Red River Valley, it looks like the bulk of the snow with this storm will fall over western and northern Manitoba. Here in the valley, the best current indications are that we’ll see a couple centimetres of snow. There are a few outlier models that suggest a secondary shortwave could produce heavy snow over the region in the second half of the night, but I don’t have a lot of confidence in that. I’ll be providing updates via our Facebook and Twitter pages tomorrow night.

  • RDPS Snowfall Forecast valid Monday Night (00-12Z Tuesday March 7, 2016)

The strong winds will persist all night, which when combined with a couple centimetres of new snow may be enough to create local areas of poor visibilities in blowing snow. Temperatures will drop to a low near -10°C.

Tuesday will bring more periods of snow to the Red River Valley with continuing strong winds out of the west. Temperatures will remain steady near around -11 or -12°C. Temperatures will drop to around -16°C on Tuesday night with more strong winds. Any remaining light snow should taper off overnight.

Wednesday will bring an end to the influence of this storm system. The clouds should break up a bit as the winds taper off through the day. Temperatures will remain cool with a high near -10°C. Expect some more clear breaks overnight as an Arctic ridge pushes into the region. Temperatures will fall well below normal with a low near -19°C.

The Big Picture

Rainfall

Rainfall will be the primary story for much of southern Manitoba today as an area of showers develops ahead of a warm front lifting northwards from the United States.

Areas in Manitoba that will see rainfall today.

The biggest unknown is exactly how much rain will fall, which will depend on how intense the area of showers can manage to develop. At the moment it looks like most areas will see 2-5 mm, however there is the potential for higher widespread amounts of 10-15 mm further north in the Interlake. Should any potent convective cells develop, which may happen anywhere in the rain area today, they may be capable of producing isolated accumulations of 10-20 mm.

The rain will move out of the province this evening, replaced by snow.

Freezing Rain

The risk of freezing rain will appear today through western Manitoba into the Interlake.

Freezing rain is possible over western Manitoba & the Interlake today and into tonight.

The threat for freezing rain will move into western Manitoba this morning and persist until midday. Accumulating freezing rain is possible, with the risk for several mm of ice accumulation. This threat will then lift into the Interlake for the afternoon and onwards into northern Manitoba tonight.

Snowfall

The major impact from this storm will the snowfall and associated winds.

A major snowfall event will occur over eastern Saskatchewan, western Manitoba and northern Manitboa with this winter storm.

The snow is already falling across eastern Saskatchewan and northern Manitoba and will spread eastwards into western Manitoba for the afternoon. Snowfall amounts will be major, with upwards of 40-50 cm expected to fall through the heaviest band in Northern Manitoba. Further south, a north-south swath of 10-30 cm will pile up by Tuesday morning. There will be a relatively sharp cut-off from the heavy snow to just minor accumulations on both the eastern/southeastern and western flanks.

This heavy snow will combine with strong northwest to westerly winds to produce an extended period of blizzard conditions, likely lasting over 24 hours. If you are in the areas that will see heavy snow move in today, it will be best to avoid all travel until conditions improve.

Long Range

Once everything finally calms down on Wednesday, we’ll move into an extended period of below-normal temperatures with daytime highs falling to the mid-minus teens and lows falling below -20°C. No precipitation is expected in the second half of the week.

Winnipeg’s seasonal daytime high is currently -4°C while the seasonal overnight low is -14°C.

Temperatures Soar For The Week Ahead

Very mild temperatures will spread into Southern Manitoba this week sending daytime highs soaring to over 10°C above normal for mid-January.

The week will start with one more day with seasonal temperatures in Winnipeg & the Red River Valley as mainly sunny skies combine with light winds as temperatures climb to a high near -6°C. Temperatures will dip to around -11°C tonight as winds begin to pick up from the south in advance of an incoming warm front.

Tuesday and Wednesday will bring the arrival of warmer weather to the region as a warm front sweeps eastwards across the province. Tuesday will see winds increasing out of the south to around 30-40 km/h while temperatures climb to a high near -3°C late in the day. The winds will diminish in the evening and temperatures will dip to a low near -5 or -6°C. On Wednesday, the warm air will push even further east, sending daytime highs to the 0°C mark in the Red River Valley with fairly light winds. Expect temperatures to dip down to around -2 or -3°C on Wednesday night.

The forecast 850mb temperatures show clearly the push of mild air across the Prairies through mid-week.

Both Tuesday and Wednesday have some uncertainty as to how much cloud will move in. At best, we could expect mixed skies, however I think it will lean towards the cloudier side than the sunnier side. Having fairly cloudy conditions as we warm up to the freezing mark in January would not exactly be uncommon for this area.

Long Range

The second half of the week will continue to bring mild temperatures with daytime highs near the freezing mark and variable cloudiness. Heading into the weekend, it begins to appear that the weather will begin to get a bit busier as the storm track shifts towards our region. It looks like, at this point, Saturday may bring a chance of rain or freezing rain, but amounts would be fairly light. The remainder of the weekend looks cloudy and mild.

Heading into the start of next week, models are beginning to converge on the development of another Colorado Low that would impact our region. It’s still very early, so as usual plenty can change between now and then, but at the moment it appears that this system could bring snow into Winnipeg & the Red River Valley sometime Monday and persist through Tuesday. Forecast storm total amounts are generally in the 10-20 cm right now. We’ll be keeping an eye on this system as we get closer and things begin to shape up more.

Winnipeg’s seasonal daytime high is currently -13°C while the seasonal overnight low is -24°C.

Warm Weather Brings Unsettled Conditions

Today will mark the start of a prolonged spell of unseasonably warm weather for Southern Manitoba. A strong west-to-southwest flow aloft will begin building into the region today, ushering in much milder Pacific air which will help daytime highs climb above the freezing mark. The milder weather will bring unsettled weather with numerous chances for snow or rain along with the risk for freezing rain over the coming 3-5 days.

Today will bring soaring temperatures as gusty southerly winds develop and raise our temperatures from sub-minus 20 values this morning to around -4 or -3°C by the end of the day. While winds will be light early this morning, they will pick up towards midday to 30-40 km/h out of the south as the warm front towards the Red River Valley. As the warmer air advances eastwards, it will produce scattered flurries that will pass through much of the Red River Valley.

Temperatures will remain steady or drop slightly on Thursday night as more warm air surges northeastwards ahead of an incoming low pressure system. Any remaining flurry activity will taper off overnight, but by Thursday morning the potential for precipitation will return.

RDPS Precipitation Type Forecast for Thursday February 18, 2016
RDPS Precipitation Type Forecast for Thursday February 18, 2016

Thursday will be a mild but messy day. A low pressure system tracking across the Southern Prairies will spread a wintery mix of precipitation through the region with pretty much anything possible. With a high of just +1°C, much of the day will bring the potential for flurries or ice pellets, with the risk of freezing rain. At this point it doesn’t appear that amount will be too significant for the Red River Valley, but with a significant chance for freezing precipitation, we’ll be keeping close tabs on it.

Winds will be moderate throughout Thursday morning out of the southeast to about 30-40km/h. Temperatures will climb to near the 0°C mark and then remain there through the remainder of Thursday and through Thursday night. The chance for any type of precipitation (flurries, freezing rain, rain showers) will likely continue through Thursday night.

Friday will see even warmer air push into the Red River Valley with a daytime high near +2°C expected. There will continue to be a chance for flurries in the morning transitioning to rain showers. Winds will remain light until later in the day when a weak cold front swings through and ushers in winds near 30km/h out of the west-northwest.

Long Range: Mild Weather Continues

Looking forward, it looks like the warmer temperatures will remain in place for a while yet. This weekend will remain warm with daytime highs near 0°C on Saturday and -5°C on Sunday, with chances for snow on both days.

CPC 6-10 Day Temperature Anomaly Outlook
CPC 6-10 Day Temperature Anomaly Outlook

Further on into next week, temperatures are forecast to continue above seasonal for this time of year as shown above in the CPC’s 6-10 day temperature outlook.

The normal daytime high for Winnipeg is currently -8°C and the normal overnight low is -18°C.

Mild Weekend Then Into A Colder Stretch

A low pressure system crossing the Prairies will bring another wave of unseasonably mild air into Southern Manitoba and help temperatures climb above 0°C for the second time this week. Heading into the latter half of the weekend, unsettled weather will develop over Southern Manitoba bringing flurries as cooler air begins gradually slumping southwards out of the Arctic and across the Prairies.

Today will be a much nicer day for Winnipeg than it appeared like it would be earlier this week, all thanks to a more northern track for today’s low pressure system crossing the province. As a result of this trajectory, Winnipeg will still see the warmth we expected before, but much less of the precipitation, which will now mainly fall through Central Manitoba and the Interlake before heading off into Ontario.

For the city, today will start off with a chance of…well, just about anything—snow, freezing rain, or showers—as a warm front pushes through and brings our temperatures above zero. As the warm front pushes off to the east relatively early in the day, we’ll be left with skies on the cloudier side and temperatures in the +1-2°C range. Windswe will start out of the south at around 30-40km/h before shifting to westerly behind the warm front at similar speeds. The chance for showers will redevelop mid-day and through the afternoon as a little bit of cooling aloft moves across the region. Expect temperatures to drop to around -2°C tonight with a few clear breaks developing.

RDPS 12hr. QPF Forecast for Friday January 29, 2016
This RDPS forecast showing accumulated precipitation through Friday shows how most of the precipitation is expected to our north and east

Saturday will bring more warm weather cloudier skies once again, although a few sunny breaks are certainly possible and the southwestern Red River Valley may actually end up seeing a fair amount of sunshine. Temperatures will climb to around +1°C with lighter winds than Friday.

A cold front will begin slumping southwards through the region on Saturday night. This will bring cooler temperatures and send our overnight low down to around -11 or -12°C under cloudy skies. Alongside the cooling will be a chance of some light flurry activity.

Sunday will be a cooler day with a high in the near -6°C or so. Under mainly cloudy skies, Winnipeg will see a slight chance for flurries throughout the day thanks to favourable temperatures throughout the lower atmosphere. This cooler weather will mark the leading edge of a return to seasonal and below-seasonal temperatures for a short while.

Long Range: Colder, But For How Long?

Looking forward into next week, it looks like cooler weather will return to the Prairies as the conditions that have supplied the warmer weather to the region over the past week collapse southwards and allow cooler Arctic air to slump southwards.

GEPS Maximum Temperature Forecast valid February 1-6, 2016
GEPS maximum temperature forecasts valid for the February 1-6, 2016 time period

The GEPS[1] is showing a transition into slightly below normal conditions next week. This image shows the maximum temperature expected in each 6-hour time period from Monday through Saturday. Ensemble forecast systems produce numerous forecasts, and then statistical analysis can be done on the output to (in theory) produce more accurate forecasts, especially in the long range. In the image above, the easiest way to understand it is that the value along the line is a fairly reasonable "most likely" temperature, while the red shading on either line represents the certainty; if there’s little shading extending from the line that means there is high confidence in the values; if there’s a lot of shading extending above and below the line, it means that there’s more uncertainty associated with the forecast at that time.

The GEPS shows fairly reasonable confidence that daytime highs will be dropping into the -15 to -20°C range early next week, a fair amount below the seasonal highs of -11°C for this time of year. With daytime highs in that range, it’s likely overnight lows will dip into the mid-minus 20’s. Heading toward the end of the week, though, there begins to be a lot more uncertainty on the weather pattern, so we’ll just have to wait and see for when the warm-up returns!


  1. Global Ensemble Prediction System  ↩