Seasonal Weather Leads To Blustery End of Week

Winnipeg will see near-seasonal temperatures over the coming days with some light flurry activity mixed in before a big warm-up moves in for the weekend. The transition to warmer weather won’t be particularly graceful, however, as a howling southerly wind develops on Friday, making for a rather unpleasant shift.

The weather in Winnipeg through today and tomorrow will be dominated by the gradual arrival of a weak Arctic high that will slowly build southeastwards out of the Northwest Territories across Saskatchewan and Manitoba. Weak is the key descriptor of this ridge; it will bring with it little in the way of cold air nor will it be able to muster up much clearing either.

That said, today’s weather will be relatively pleasant, all things considered. Skies will be mainly cloudy through the day with some occasional light flurry activity. Temperatures will climb a little bit from where we start off to about -10°C with fairly light winds throughout the day. Tonight will continue to bring mainly cloudy skies—although a few clear breaks are possible—and temperatures dipping down to about -18 or -19°C. If more clearing develops than is expected at this point, the overnight lows could dip closer to about -23°C.

Tomorrow will bring very gradual clearing to Winnipeg with the morning likely starting off fairly cloudy and slowly becoming mixed to mainly clear throughout the day as the Arctic ridge slides into the Red River Valley. With the arrival of that system, the daytime high tomorrow will be cooler at around -15°C with a light northerly wind. There’s a slight chance of some flurries through the early morning, but for the most part no precipitation is expected on Thursday. Expect a low on Thursday night near -21°C under partly cloudy to mixed skies.

Friday will be…unpleasant. As many who have lived in Winnipeg for a while know, whenever a big warm-up is on the way there is often "the day" before the warm weather arrives; a day where it’s rarely as nice as it sounds like it’s going to be and those famous southerly winter winds make an appearance. Friday will be that day.

As the Arctic ridge pushes past and moves to our southeast, it is quickly replaced by a strengthening low pressure system moving across the Prairies. As the low moves into eastern Saskatchewan and begins spreading warmer air aloft over Southern Manitoba, its relatively close proximity to the Arctic ridge will result in a tight pressure gradient over the Red River Valley, oriented very favourably for the development of strong southerly winds. While starting the day off light, the winds through the Red River Valley will increase to around 30 gusting 50 km/h by noon, and then further strengthen to 40-50km/h gusting to 70km/h by the evening hours.

GDPS MSLP & Surface Wind Forecast for Friday
The GDPS shows the strong southerly winds (emphasized in yellow) expected over the Red River Valley on Saturday.

Temperatures will gradually climb to around -12 or -11°C by late in the afternoon—although it will feel closer to -25 throughout much of the day due to the wind chill. Temperatures will continue to rise overnight as the warmer air finally begins working its way into the valley; by Saturday morning the temperature is expected to climb to about -8°C in Winnipeg.

With strong warm air advection aloft and the surface flow dominated but the outflow from an Arctic ridge, it’s likely that Friday will be fairly cloudy as stratus streams northwards out of the ridge.

Warm Weekend Ahead

This weekend looks beautiful with temperatures well above seasonal expected throughout the Red River Valley. In Winnipeg, the temperature is expected to climb all the way to around the freezing mark under mainly cloudy skies. Sunday looks fairly nice, perhaps evening bringing some sun to the region, with daytime high closer to the -5°C mark.

Temperatures are expected to return to seasonal values for the start of next week.

Mild Start of Week but Change is Coming

The temperatures look to remain above average for the start of this week as the storm track remains well to our north, and the cold Arctic air remains locked up to our north….for now.

Although today will be fairly warm, with a high near -5°C, the wind will be a factor in making it feel cooler than it actually is. Sustained southerly winds could reach 40km/h, with gusts in the 60km/h range tomorrow, in the afternoon and evening. The overnight low will be a fairly mild one, with temperatures only dipping to around -12°C.

RDPS Forecast Winds for Monday Afternoon
The RDPS forecast shows a core of strong outflow winds running across the Northern Plains and through the Red River Valley into Manitoba on Monday afternoon.

Tomorrow looks to be more of the same temperature-wise, with temperatures reaching -6°C. The strong winds should ease up early in the morning – only reaching 10-15km/h on Tuesday. Skies should remain partly cloudy throughout the day, but overnight cloud cover will increase, associated with a system to our south.

On Wednesday cloud cover is expected to persist and even a few flakes are possible in the morning and early afternoon, but amounts won’t be significant. The high looks to be slightly cooler than previous days at around -8°C. North-easterly winds will be in place through the day but they won’t be very strong; only around 10km/h or so.

Long Range

Long range models are hinting at a possible snow event at the end of this week. Right now models show the bulk of the snow staying to the southeast of Winnipeg, into northwestern Ontario though. Unfortunately, cold Arctic air will be advected into our region behind this system, resulting in normal to below normal temperatures by the weekend.

Winter Arrives

Environment Canada made headlines with the special weather statement for Winnipeg issued Monday with a referential start: winter is coming. And how.

Today will mark the beginning of a harsh slide into winter after a essentially a month of temperatures well above seasonal for this time of year. The change in the pattern will be brought courtesy a rather peculiar weather setup that will see a relatively weak Colorado Low moving north through Minnesota into Northwestern Ontario merge together with an Alberta Clipper quickly moving eastwards across the Prairies. Each system is moderately potent in their own right, but when combined, they will form a new storm system that will rapidly intensify, driving strong northwesterly winds through the province alongside the first significant snowfall for many regions of Southern Manitoba.

Today will start deceptively. Relatively light winds and temperatures climbing towards 5 or 6°C will give a false sense of security betrayed only by the increasing cloud cover that will build in through mid-day into the afternoon. Some light rain will develop over the Red River Valley this afternoon, which will mark the end of our above-seasonal temperature streak and usher in winter. As the rain moves into the region, winds will pick up out of the northwest to around 50km/h sustained with gusts as high as 70–80km/h. The rain will switch over to snow sometime in the evening and likely begin piling up fairly quickly as the strong winds rapidly cool the ground and other surfaces.

The strong winds and snow will persist through tonight as temperatures dip down towards –3°C or so as colder air begins filtering into the region. With snow piling up and such strong winds in place over the Red River Valley, it’s quite likely that driving conditions become quite poor as roads freeze, become ice covered, and see reduced visibility in blowing snow.

AWM Snowfall Forecast issued November 18, 2015
AWM Snowfall Outlook issued November 18, 2015

Thursday will continue to bring light snow and strong winds to the region as temperatures remain around –4°C or so. The winds will be a bit lighter than at their peak, but will likely remain near the 40 gusting 60km/h mark through much of the day before beginning to taper off in the evening. Overnight, other than some lake-effect snow streaming southeastwards off of Lake Winnipeg, there’s likely to be just a few flurries lingering in the region. Temperatures will dip down to –6°C for the overnight low.

In general, around 5–10cm of snow is likely to fall with this system through southeastern Manitoba, the Red River Valley and northwestwards into Parkland Manitoba. Exact amounts will depend on the timing of the change-over from rain to snow and how quickly the snow begins accumulating instead of melting on the ground.

Friday will be a mainly cloudy day with just a very slight chance of light, scattered flurries. Temperatures will recover only a degree or two from the overnight low with highs around –4°C. There may be a few clear breaks through the Red River Valley on Friday night, but overall there will still be a fair amount of cloud as temperatures head towards an overnight low near –10 or –11°C.

Colder Weather Continues Through The Weekend

The cooler weather, which while a significant drop from what we’ve been experiencing is, in actuality, just a couple degrees below seasonal values for this time of year, will persist through the weekend.

NAEFS 8-14 Day Temperature Anomaly Outlook valid for November 25 to December 2, issued 12Z November 17, 2015
The NAEFS is showing a trend towards seasonal temperatures for the remainder of November.

Daytime highs around –5 or –6°C will be in place over Winnipeg & the Red River Valley this weekend, with a chance of some more flurries on Saturday improving to sunnier fare on Sunday. Overnight lows will be in the low minus single digits. So, while it may be a huge change from the weather we’ve been having, we’ll be shifting to more seasonal weather for the end of November.

Grey Skies Return on Monday

Grey and drizzly weather return today as a surge of moisture from the south generates an area of low cloud over southern Manitoba. It looks like we may see the sun again by midweek.

Monday will be overcast with periods of drizzle as a surge of moisture generates low cloud over southern Manitoba
Monday will be overcast with periods of drizzle as a surge of moisture generates low cloud over southern Manitoba

Monday

Today will be a grey, dreary day in southern Manitoba. A strong push of low-level moisture from the south will generate a broad area of low-cloud, bringing periods of drizzle to southern Manitoba throughout the day. Temperatures will remain relatively mild, in the mid single digits, but with the drizzle and wind it won’t feel particularly comfortable. Wind speeds will be gusty, at 30km/h gusting to 50km/h, out of the south-east.

Tuesday

Tuesday will see generally cloudy skies stick around in southern Manitoba, but we may see some clearing by late in the day. The flow will shift to westerly on Tuesday, allowing a drier airmass to move into the region. However, it doesn’t look like this drier air mass will arrive in time for us to see clear skies before sunset. Winds will be westerly at 20km/h with temperatures in the mid single digits.

Wednesday

We should finally see sunnier conditions on Wednesday as we sit between two approaching low pressure systems. Current forecast models suggest we’ll remain in a dry airmass for most of Wednesday, before the risk of precipitation increases again on Wednesday night. Winds should generally be light, with temperatures in the mid single digits.

Long Range

It looks like we’ll see a fairly stark change in the weather on Thursday as a powerful cold front ushers in a more arctic-like airmass. Very strong winds are expected on Thursday in the wake of this front along with decreasing temperatures. Unfortunately, we may see some accumulating snow with this system, though it’s too early to say how much can be expected. It still appears that the overall pattern will remain above normal for the foreseeable future, but as we move further into the winter season snow and cold are inevitable.