Category: Forecasts

Cold Weather Continues

Brad Leave a comment

The cold weather continues in Winnipeg for much of this week with only a brief respite mid-week of some near-seasonal temperatures. Snow-wise, a weak system moving through today will bring a couple centimetres of fresh snow, but otherwise no significant snowfall is in the forecast.

Today’s weather will be dominated by a weak shortwave disturbance sliding southwards through the province. Light snow will push into the Red River Valley from the northwest this morning and taper off this evening. Accumulations will be relatively low with this snow; for the most part, just 1-2cm is expected to accumulate. As the system begins heading past us this afternoon, gusty northwesterly winds to 20-30km/h will develop, making it feel more like the minus 30’s than the high of -20°C.

Multi-spectral satellite imagery of approaching low pressure system.
This morning’s satellite imagery reveals the low pressure system that will slump to the southeast and bring light snow to the region today.

Behind this system, another Arctic ridge will build into the southern Prairies, reinforcing the cold air. Here in the Red River Valley, temperatures will dip to around -26°C tonight with wind chills in the -33 to -37 range. In the southwest corner of the province, temperatures could fall as far as -30 to -31°C, which would result in wind chills near or slightly below -40.

Tuesday will be a fairly quiet day over Winnipeg & the Red River Valley with mixed skies and a high near -20°C. Winds will be fairly light.

The next system moving into the Prairies will spread cloud across Southern Manitoba on Tuesday night, somewhat limiting our overnight low to around -24°C.

3hr QPF from the RDPS valid overnight Tuesday.
This forecast from the RDPS for Tuesday night shows a broad warm front pushing into Manitoba with an area of light snow ahead of it.

Wednesday is a bit trickier, but either way things pan out, the weather won’t be too significant. The big story will be that near-seasonal temperatures will finally move into the Red River Valley with daytime highs climbing into the -13 to -15°C range. Skies will be mainly cloudy.

Depending on how far east the disturbance moving through the region pushes, we may see some light snow through the day. If it remains to our west, as guidance suggests, it seems probable that we could see some very light flurry activity across the region.

Temperatures will remain comparatively mild on Wednesday night with overnight lows near -20°C.

Colder air is set to return for the second half of the week with another shot of sub-20°C high temperatures likely this weekend.

Arctic Chill Settles Over Manitoba

Brad 2 Comments

Winnipeg will see some of the coldest weather of the winter as Manitoba falls under the influence of the infamous Polar Vortex. Unlike other brief cold snaps seen this winter, this cold spell looks to be rather persistent, with only one brief warm-up on the horizon before the Arctic air returns.

Today will start with a few remaining flurries pushing out of the region as a cold front sweeps through the province. Winds will be out of the northwest at 20-30km/h for much of the day. Once the flurries move out this morning, the Red River Valley will be left with mainly cloudy skies and falling temperatures. By late this afternoon, the temperature will sit around -18 or -19°C.

Skies will remain fairly cloudy tonight as temperatures dip to -26°C.

Forecast 850mb Temperatures — RDPS 00Z Jan 08, 2016
The core of the coldest air in North America will be anchored over Manitoba on Saturday morning.

Saturday will mark the full arrival of the Arctic air. The high temperature will be limited to only -21°C with light northwesterly to westerly winds. There’s some uncertainty as to how much cloud cover will remain in the area, but it appears that we’ll likely see mixed skies here in Winnipeg. A little bit of clearing will move in on Saturday night as temperatures dip to around -25°C.

Sunday will continue the cold trend with daytime highs near -20°C under partly cloudy skies and light south to southwesterly winds. Sunday night will continue seeing partly cloudy skies with a low near -25°C.

Weather Roller Coaster Next Week

Unfortunately, next week doesn’t look to offer too much of a reprieve from the cold. This outbreak of colder weather has been driven by a weakening of the Arctic Oscillation (AO) which has allowed colder air to spill southwards. Despite the strong El Niño, the reality often is that cold air is king, and it’s managed to shunt out the warm air. The coming week will be a battleground between the blocking pattern of the Polar Vortex and the attempt for a more typical El Niño pattern featuring warmer weather and a more progressive pattern.

The first half of next week looks fairly cool with daytime highs in the -15 to -20°C range and a slight chance of snow on Monday into Monday night. There is hope for a more substantial warm-up mid-week, however.

A surge of significantly warmer air is expected to spread eastwards on Tuesday with some light snow associated with it. General consensus is that an Alberta Clipper will develop over Northern Alberta and then race southeastwards along the baroclinic zone, flattening it out and sweeping cold air southwards in its wake.

Exactly how warm it manages to get in Winnipeg will depend substantially on the timing and exact location of the setup. Some forecasts show the warm air fully pushing into the region and resulting in daytime highs mid-week near -8°C, while others have a more southerly track and occlude the warm air out to the south quickly and keep temperatures fairly cold.

After the passage of the clipper and any associated snow, the Polar Vortex is expected to retrogress and usher another shot of very cold air into Manitoba.

Temperatures Plummet for Weekend Arctic Outbreak

Brad Leave a comment

Winnipeg will be re-introduced to winter this weekend as a major pattern shift will usher in one of the coldest outbreaks of the season as bitterly cold air surges out of the Arctic and plummets much of North America into below-normal temperatures.

The next few days will see Winnipeg socked in under extensive cloud cover. While the lack of sun will be a little disheartening, the thick blanket of cloud will moderate temperatures substantially, staving off the cold weather for a little longer.

Both today and tomorrow will be mainly cloudy days with daytime highs around -7 or -6°C and overnight lows in the -10 to -12°C range. A weak ridge of high pressure anchored through the region over the coming days will also keep winds fairly light. All in all, it looks like a relatively pleasant couple of January days.

On Thursday night, a disturbance rippling through the region aloft will help deepen an inverted trough extending to the north-northwest from a low pressure system moving through Iowa. These two things combined will help support an area of light snow that will spread across the province from central Saskatchewan.

AWM Snowfall Forecast for January 7-8, 2016
A large area of light snow is expected to move thorugh the Red River Valley on Friday. Heavier snow is expected through east-central Saskatchewan into Swan River & Dauphin.

Snow will begin through Thursday night from west to east and will be fairly light, with just 2-4cm total accumulation expected by the time it tapers off on Friday afternoon.

Temperatures will be fairly steady throughout the snowfall on Friday, either remaining near Thursday’s overnight low or perhaps recovering just a degree or two. As the snow tapers off in the afternoon, gustier northwesterly winds will build into the region—at this point it looks like they’ll be around 30km/h—and begin ushering in colder air.

Skies will clear on Friday evening allowing temperatures to plunge to about -21°C by Saturday morning.

Long Range: Cold Weekend

This weekend will see bitterly cold weather settle in over the province as the core of the coldest air on the continent rotates over the region. [1]

GDPS 850mb Temperature Forecast valid Saturday 12Z 09 January 2016
The GDPS 850mb temperature forecast shows the core fo the coldest air on the content rotating into Manitoba.

This very cold air mass will result in temperatures steady near around -20°C on Saturday, but quickly dropping into the lower -20’s on Saturday night. Sunday will likely see a high near -21 or -22°C with temperatures remaining fairly steady on Sunday night as some warmer air begins working into the region. Skies will be mainly clear through the weekend with little wind.

Looking further ahead into next week, near-seasonal temperatures to slightly below-seasonal temperatures are expected. Seasonal highs are near -13°C for this time of year.

  1. Some may wonder why the coldest air mass on the content won’t result in the coldest temperatures on the continent, and the answer to that is complicated. The most basic reason is simply that compared to our Arctic neighbours, we actually have sunshine at this time of year. There are a host of other reasons, too, rooted in prior conditions.  ↩

Mild Start of Week but Change is Coming

Matthieu Leave a comment

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.