Colder This Week

This week will be see temperatures trend below seasonal as a surge of arctic air comes down from the north.

Colder weather is expected this week behind the weekend's departing low pressure system
Colder weather is expected this week behind the weekend’s departing low pressure system
-12°C / -22°C
-17°C / -30°C
Mainly sunny
-18°C / -25°C
Mainly sunny

Today will be slightly below seasonal as colder air filters southward behind the weekend’s strong low pressure system. High temperatures will be in the low minus teens under clearing skies. Winds will remain stiff out of the north-west at 30km/h gusting to 50km/h. There may still be a bit of drifting snow on the highways with these wind speeds, but heavy blowing snow is not expected.

Tuesday will see a further drop in temperatures as that arctic air mass becomes more entrenched over southern Manitoba. High temperatures will be in the upper minus teens under mainly sunny skies. Winds will remain northerly at about 20km/h. Tuesday night is expected to be quite cold due to the presence of a strong surface ridge of high pressure over the area along with clear skies. Temperatures are expected to drop to around -30C, but luckily wind chill values should not be a significant factor due to the light winds with this high pressure system.

Wednesday will remain cold, with temperatures staying in the upper minus teens. The good part of this colder pattern is that we should continue to see sunny skies on Wednesday. We will be under the centre of a surface high on Wednesday, bringing generally light winds to the region.

Long Range

The long range forecast shows cold conditions sticking around for the rest of the work-week. Models suggest we should warm back up to above-seasonal conditions by the weekend into next week. In the even longer range it appears that we may see one more arctic blast later next week before a more prolonged warm period takes hold towards the end of the month.

Weekend Storm To Bring Snow & Warmer Weather

Warm weather is on the way for Winnipeg this weekend as a strong low pressure system developing over Northern Alberta spreads mild air eastwards through the Prairies. This storm system will then slide southeastwards across the Prairies, bringing a moderate snowfall event to Manitoba primarily through Saturday afternoon and Sunday, followed by falling temperatures, gusty winds and blowing snow.

-6°C / -11°C
Cloudy with a few flurries
-1°C / → -1°C
Cloudy; snow intensifying through the afternoon
↓ -8°C / -13°C
Light snow

Winnipeg will see mainly cloudy skies today as the city remains locked underneath a tight baroclinic zone. [1] There will be a continued chance of occasionally seeing some of the flurry activity that developed last night over the city, however no real accumulations of snow are expected today. Temperatures will be fairly pleasant with a daytime high near -6°C, which is 4°C above the normal high of -10°C for this time of year.

The chance for any flurry activity will diminish tonight, but the cloud will stick around as temperatures dip to around -11°C for the overnight low.

Storm System Moves in on Saturday

Saturday will bring the arrival of both warmer weather and the storm system that will bring a new batch of snow to the region. First the good news: temperatures will be on their way up through the entire day. From the morning low near -11°C, temperatures will gradually climb to near -5°C midday and then up to near -1°C by evening. Temperatures will then remain fairly steady through the night, wavering around the -1°C mark. Cooler air will begin working into the region on Sunday, dropping the temperatures in Winnipeg to around -8°C by the evening.

AWM Snowfall Forecast for February 6/7, 2016
Updated AWM Snowfall Forecast for February 6/7, 2016 (Original here)

While some flurries are possible through the morning, the real snow will develop through the afternoon hours as the low centre of the storm begins moving into Southern Manitoba. Snow will intensify into the evening and the heaviest snow of the storm will be through Saturday night. On Sunday morning the snow will likely begin to ease, but continue to persist much of the day. By the time all is said and done, it looks quite likely that essentially all of Southern Manitoba will have seen at least 5cm of new snow before things taper off on Sunday night.

The heaviest amounts will fall to the north of the low track, which, given that it’s still a day and a half out, could change. The current agreement seems relatively dependable, however if it does end up shifting south even just a little, it’s possible that Winnipeg could surpass 10cm.

Although this system has the potential of producing a lot of snow, it doesn’t look like it will qualify for a snowfall warning from Environment Canada, which requires 10cm to fall within a 12hr. time period. This system will produce higher amounts more through it’s longer residency time than its intensity. That said, it’s still early for a lot of things with systems like these; we’ll be keeping an eye on it and updating forecasts if it looks like it’s going to change significantly from current expectations.

Lastly, there will be a bit of wind with this system too. Winds won’t be too bad on Saturday, however for a short while in the afternoon winds may climb up to around 30-40km/h out of the southeast. Winds will diminish overnight before picking up on Sunday out of the northwest. Blowing snow will be an issue on Sunday as the northwesterly winds increase to 40 gusting 60km/h and combine with the fresh snow. Through the Red River Valley, the strong winds will be in place by mid-day Sunday and persist into the late evening hours, so if you have plans to travel on Sunday afternoon or evening, prepare to give yourself some extra time to account for poor visibilities and driving conditions. For those reading this in southwestern Manitoba, the stronger winds will be in place by Sunday morning and persist into the overnight period as well, making blowing snow an issue all the way west into southeastern Saskatchewan.

Long Range: Colder Weather…But Only Briefly

Behind this storm system, cooler air will begin slumping into the Prairies, returning temperatures to seasonal values. Another batch of snow is possible Tuesday night as another disturbance moves through the region, which will usher in a pattern change that will see southwestern Manitoba clipped by several systems while even colder air works into the Prairies.

NAEFS 8-14 Day Temperature Anomaly Forecast — Valid February 13-20, 2016
NAEFS 8-14 Day Temperature Anomaly Forecast — Valid February 13-20, 2016

Into the second half of next week, below-seasonal temperatures will begin moving into the province with daytime highs slumping into the low minus teens and overnight lows dipping below -20°C. This cooler weather will likely persist into the early parts of the following week before a moderating trend begins, shown by the higher probabilities of cooler-than-normal weather in the NAEFS forecast above.

The seasonal daytime high for February 5th in Winnipeg is -10°C, while the seasonal overnight low is -21°C.

  1. A baroclinic zone is an area where there is a strong temperature gradient across relatively short distances, either at the surface or aloft.  ↩

Seasonal Temperatures & Occasional Snow

Near-seasonal temperatures are on the way for Winnipeg through the remainder of this week with multiple chances for light snow as several weak disturbances slide across the region.

-10°C / -15°C
Increasing cloudiness, then light snow
-11°C / -18°C
Mainly cloudy with a slight chance of flurries
-10°C / -14°C
Cloudy with a chance of flurries

Today’s weather will be dictated by a weak low pressure system moving through the region that will spread more cloud and snow across Southern Manitoba. Although the snow will be widespread as it gradually pushes eastwards across the province, it will also be quite light. The grand-total for around 4-6 hours of snow will be just 1-2 cm, with some areas that see little-to-no accumulation. Here in Winnipeg, we’ll see some sun through the morning, then increasing cloud with some light snow starting late in the afternoon. It will be pleasant for early February, however, with daytime highs around -11°C and light winds. Expect temperatures to dip to around -15°C tonight under mainly cloudy skies.

RDPS-based precipitation forecast valid from 18Z - 06Z February 3/4, 2016
RDPS-based precipitation forecast showing snow over Manitoba through Wednesday afternoon & evening

Thursday will be a benign day with mainly cloudy skies, daytime highs once again near -11°C for Winnipeg, and light winds. There’s a very slight chance of some flurries thanks to the temperature profiles through the lower atmosphere, but if they do develop, they will be quite weak. Temperatures will drop to about -14°C on Thursday night with cloudy skies as the next low pressure system moves in from the west.

Friday will be another cloudy day with daytime highs climbing a couple degrees higher to around -9°C. There’s a decent chance of some flurry activity through the Red River Valley as the next low pressure system tracks through the region. Temperatures will dip to around -14°C on Friday night under cloudy skies.

Long Range

The long-range outlook shows a fairly significant pattern change next week, but not before things turn a little more unsettled.

Through the weekend and into the first half of next week, the weather looks to turn more unsettled as the storm track shifts over Manitoba. No major snowfalls are expected at this point, but several relatively strong lows will likely move through the region, at least bringing a little more variability to the temperature and some windy conditions at times.

GFS-based forecast of 850mb temperature anomalies for the end of next week
GFS-based forecast of 850mb temperature anomalies for the end of next week

A major large-scale pattern change begins early next week as the polar vortex slumps southwards into Northern Ontario as large scale upper-level ridging takes place over the west coast of North America. This combination will shift winds at all levels over Manitoba to northerlies straight out of the Arctic, and a surge of colder air will blast southwards in response. This will likely happen in multiple stages with a weaker shot mid-week and then a stronger surge at the end of the week. The image above shows the GFS forecasting 850mb temperatures [1] over 10°C below normal for next Friday.

If this forecast comes to fruition, then through the latter half of next week daytime highs would fall into the -15 to -20°C range.

The colder air doesn’t appear to be likely to stick around for too long, though, with seasonal temperatures building back in by the end of the weekend.

Seasonal daytime highs in Winnipeg for early February are -10°C while seasonal the overnight lows are -21°C.

  1. 850mb is approximately 1.5km above the ground.  ↩

Seasonal Conditions Early This Week

This week will start out with near seasonal conditions as temperatures stick near the -10C mark.

-9°C / -17°C
Mainly cloudy with chance of flurries
-11°C / -23°C
Mix of sun and cloud
-11°C / -24°C
Mainly cloudy with chance of flurries

Today will see temperatures around or just above -10C. Skies will be mainly cloudy with a chance of flurries as a weak system passes to our south. Given the slack pressure gradient over southern Manitoba, winds will remain light and variable.

Tuesday will be slightly cooler than Monday, with temperatures around or just below -10C. An arctic air mass to the north will continue gradually sliding southward, allowing slightly colder weather to prevail. The drying associated with this colder air mass is expected to help clear skies a bit, although it looks like we won’t see completely sunny skies, but rather a mix of sun and cloud. Winds will be north-westerly at about 20km/h.

RDPS Temperature Forecast valid Monday afternoon
Forecast temperatures mid-afternoon across the Prairies on Monday

Wednesday will remain near seasonal, with temperatures once again just below -10C. Skies will become cloudy again as an upper-level impulse moves through the region. This impulse may bring a few flurries to southern Manitoba, but nothing significant. Winds will shift to southerly at around 20km/h.

Long Range

Models still aren’t showing a strong signal for what the long range forecast may entail. Based on the trends in the guidance, it looks more probable that February will cooler than normal than warmer than normal, but that is just an educated guess at this point.