One Last Mild Day Before The Deep Freeze

Temperatures remain well above seasonal in Winnipeg for one more day before plummeting as a powerful cold front blasts southwards out of the Arctic.

Winnipeg will see mostly cloudy skies today as a weak impulse slides along the U.S. border. It will support an area of light snow that will spread around 2 cm of light snow across the southern Red River Valley. There’s a chance that Winnipeg will see a bit of light snow, but the snow will likely pass to the south. Temperatures will climb to a high near 0°C with winds out of the southwest at 15 to 25 km/h. The snow will move out of the region in the evening along with the cloud. Temperatures will dip to a low near -7°C with winds shifting to the west at 20 to 30 km/h.

RDPS 2m Temperature Forecast valid 21Z Monday December 18, 2017
Cold air will surge southwards as the northern cold front slumps behind the passage of the southern frontal wave

Tuesday will bring the arrival of the Arctic front as it surges southwards behind a low pressure system exiting the Arctic Prairies. Winds will shift to the northwest in the morning at around 30 km/h as temperatures fall through the day, reaching around -12°C by the evening. The cold front will bring mixed skies to the region and Winnipeg may see a stray flurry or two, but no accumulating snow is expected. Skies will remain partly cloudy on Tuesday night with winds easing as an Arctic high builds in from the northwest. Temperatures will dip to a cold low of -21°C.

Temperatures will remain quite cool on Wednesday as a low pressure system passes to the south, spreading cloud into the region alongside northeasterly winds that will tap the Arctic high to the north. Skies will remain mostly cloudy much of the day as temperatures climb to a below-seasonal high near -14°C. Winds will be light at around 10 to 15 km/h. Winnipeg may see a bit of light snow in the evening, but once again most of the snow is expected to pass to the south. The southern Red River Valley may end up seeing a couple cm, while the northern Plains of the United States see significantly more snow. Temperatures will be very cool on Wednesday night, dipping down to around -24°C.

Long Range Outlook

A low pressure system will slump through the region in the latter half of the week, bringing with it some chances for light snow, however the bigger impact will be a reinforced surge of cold air as it passes by.

GDPS 850mb Temperature Forecast valid 06Z Monday December 25, 2017
Forecasts show a bitterly cold air mass descending over the Prairies for Christmas, bringing some of the coldest air on the continent into the region

This shot of cold air will bring some coldest air in the continent into the southern Prairies, amplifying in intensity all the way until Christmas Day. Daytime highs will likely fall into the -20’s with overnight lows dipping near to or below -30°C. Christmas Day in particular looks quite unpleasant with temperatures potentially starting off below -30°C and climbing to a high in the -21 to -23°C range. Throughout the core of the coldest temperatures, which looks to from December 23rd through December 26th, Winnipeg may see its first extreme cold warning(s) of the year, with the potential for wind chill values to drop into the -40 to -45 range.

Yikes! Enjoy the warmth today and get those long johns out and ready to go!

Winnipeg’s seasonal daytime high is currently -11°C while the seasonal overnight low is -21°C.

Calm & Cool Conditions Ahead

The weather will be cool and quiet across the Red River Valley through the remainder of the work week.

Winnipeg and the Red River Valley will be wedged between a ridge of high pressure anchored over western Manitoba and a train of low pressure systems moving into Northern Ontario. While it appeared earlier in the week that some precipitation associated with the low pressure systems would work its way westward into the Red River Valley from Ontario, more recent model runs have been producing a more sensible solution that keeps everything off to the east.

That said, Winnipeg & the Red River Valley will see cloud cover associated with these systems. Today will be the cloudiest of the next three with much of the day seeing mainly cloudy skies. Skies will progress to mixed on Thursday, and then we’ll finally see straight sunshine again on Friday.

The current weather pattern is bringing below-normal temperatures to a large swath of North America.

Temperatures will remain cool, though, as the ridge and low pattern maintain a northerly flow over the region that continues to tap a cooler air mass to the north. The high temperature both today and tomorrow will hover near 6 or 7°C, with low temperatures near -5 or -6°C both Wednesday night and Thursday night. Friday may end up slightly warmer with a high near 8 or 9°C, but don’t expect anything too far removed from today or tomorrow.

The wind will continue to be quite breezy today, up to around 30 gusting to 50 km/h. They will persist until this evening, when they’ll diminish for the night, then make a reappearance for Thursday. Winds will be much lighter on Friday.

Long Range

This weekend will bring more of the same, except slightly warmer. Temperatures should edge towards more seasonal values under fairly sunny skies, although Saturday may end up more mixed than sunny.

Winnipeg’s seasonal daytime high is currently 14°C while the seasonal overnight low is 1°C.

A Brief Early-Week Cooldown

A cold front passing through the region this evening will bring the chance for some flurries this evening and return temperatures well below seasonal…for one day. Milder weather quickly returns for the remainder of the week on Wednesday.

Today will be a fairly sunny day with the Red River Valley still in the warm-sector of a major low pressure system bringing blizzard conditions to portions of northern Manitoba. Temperatures will be mild with daytime highs generally around the 4-6°C, bolstered by westerly winds at 20-30 km/h.

Things will change this evening when a cold front sweeps through the Red River Valley, bringing a chance of flurries and gusty northwesterly winds to 30-40 km/h. Temperatures will drop to around -5°C within a few hours, and then continue on to an overnight low near -13°C. Winds should taper off to around 20 km/h by midnight and remain there for the rest of the night. Skies will clear out fairly quickly behind the front.

Tuesday will see a large ridge of high pressure build into the region, bringing mainly sunny skies and winds that gradually taper off. Temperatures will be cool with daytime highs near -7°C. The northerly winds will taper off in the afternoon and then temperatures will head down to a low near -14°C overnight.

An Arctic ridge will be in place over Manitoba on Tuesday, bringing below-seasonal temperatures.

Wednesday will start off cool, but warm up through the day as a southerly wind to 30-40 km/h develops ahead of an approaching low pressure system. Daytime highs across the Red River Valley will be near 0°C as cloudy skies develop later in the afternoon. With windy conditions and warm air continuing to push eastwards overnight, temperatures will remain mild with lows near -2 to -4°C on Wednesday night. As the warm front moves through, there will be a chance for some precipitation, which could end up as anything from rain to snow or freezing rain.

Long Range

The remainder of the week looks mild with daytime highs above 0°C and generally settled conditions.

Winnipeg’s seasonal daytime high is currently 1°C while the seasonal overnight low is -10°C.

A Quiet, Unseasonably Cold Weekend Ahead

There’s not too much to say about the upcoming weekend, which is a bit of relief after the relentless storm earlier this week. Below-normal temperatures and sunny skies ahead.

Temperatures over the coming few days will be well below normal due to a rather potent Arctic ridge entrenched over the region. The upside to the colder weather is that we’ll see plenty of sunshine for the next couple days before some cloud, and warmer temperatures, moves in for Sunday.

The Arctic ridge over the Prairies will keep temperatures well below normal across a vast swath of Canada.

So for both today & tomorrow, expect highs near -15 to -13°C, with overnight lows in the -20 to -25°C range. Skies will be sunny today, but more mixed tomorrow as some cloud cover moves in from the west ahead of the next disturbance that will clip across southeastern Saskatchewan and southwestern Manitoba.

The bigger change will come on Sunday as the disturbance clips through the region. Skies will be mainly cloudy, although it should be noted that Winnipeg may see a little more sunshine if the system edges just a little bit southwards or more cloud if it tracks a bit further north. Temperatures will also warm up a tad with highs climbing towards the -10°C mark but lows will still be quite cool on Sunday night, bottoming out near -19°C.

Long Range

While a few weak clipper systems are expected to pass over southwestern Manitoba over the coming week, it looks to remain fairly dry here in the Red River Valley. Temperatures will move towards seasonal to above-seasonal mid-week, and with that shift to warmer weather we may see a bit of precipitation, but at this point it’s simply too early to tell.

Winnipeg’s seasonal daytime high is currently -3°C while the seasonal overnight low is -13°C.