Tag: #MBwx

Arctic Grip Weakens Over Southern Manitoba

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The bitter cold that’s been entrenched in the region for over a week will finally give way with temperatures gradually warming to above-seasonal values.

RDPS 2m Temperature Forecast valid 12Z Wednesday February 19, 2025
Although change is on the way, it will be cold across the southern Prairies on Wednesday morning.

Winnipeg’s weather is in for a change this week as a lobe of the Polar Vortex exits the region. It will weaken substantially over the next couple days, then rapidly shift east out of the country through the second half of the week.

As a result, there will be little change through the first half of the week, and substantial change in the second.

Over the next few days, as the weakened portion of the polar vortex dissipates, temperatures will gradually rise. By Thursday, daytime highs in Winnipeg will increase from near -20 °C to the mid-minus teens. Overnight lows will follow, rising from the -30 to -25 °C range into the minus teens.

A sprawling (and weakening) Arctic high will dominate the surface pattern, bringing sunshine and light west-northwest winds.

Long Range Outlook

While Thursday will mark the beginning of a pattern change, it will become more pronounced to end the week. The remnants of the Polar Vortex will rapidly shunt east, allowing an upper ridge to build into the Prairies from the Pacific. This will push much milder air across the region, sending daytime highs well above seasonal normals.

Daytime highs will climb to near-seasonal values on Friday, then warm closer to 0 °C on the weekend. For areas west of the Red River Valley, above-freezing temperatures are probable; we’ll have to wait to see how much mild air is able to scour into the Red River Valley to see how warm Winnipeg is able to get.

ECMWF 2m Temperature Forecast valid 00Z Sunday February 23, 2025
Much warmer weather will sweep across the Prairies this weekend, with daytime highs climbing to 0 °C or higher for most regions.

The above-seasonal temperatures will continue right through next week.

With this change, the region will shift closer to the storm track. No major systems are expected, but occasional bouts of light snow or even a wintery mix will be possible beginning this weekend and through much of next week.

Today’s seasonal daytime high in Winnipeg is -7 °C while the seasonal overnight low is -18 °C.

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First Blast of Bitter Winter Cold Incoming

Brad Leave a comment

Winnipeg will see its first shot of bitterly cold Arctic air as a ridge of high pressure builds into the region this week.

RDPS 2m Temperature Forecast valid 12Z Thursday December 12, 2024
An Arctic high will bring bitterly cold temperatures with lows in some places falling below -30 °C this week.

With the system that brought 15 to 20 cm of new snow to Winnipeg on its way out, the next system to shape the weather in the region will be an Arctic High building into the province from the north.

Before it gets here, though, a weak disturbance will move through the region today. It will bring a little bit of light snow, perhaps another 2–4 centimetres, today and then sweep a strong cold front southwards.

Temperatures will plummet behind the front as northerly winds of 30–40 km/h drive Arctic air southwards. A seasonable high near -10 °C today will quickly be forgotten as skies clear tonight and temperatures head to a low in the mid-minus 20s.

The Arctic High will be in full force through the rest of the work week. With plenty of sunshine, daytime highs will struggle to climb into the -25 to -20 °C range with overnight lows dipping back into the -25 to -35 °C range. Wind chill values will likely get close to -40 at times on Wednesday night and Thursday night.

Long Range Outlook

Temperatures will begin to moderate on Friday as the high begins to weaken and the core of coldest air moves out of the region. Daytime highs should climb back above -20 °C but breezy southerly winds will have a bite to them and produce wind chills that make it feel much worse.

Temperatures will climb back to seasonal values for Saturday and continue warming on Sunday. The region will likely see mixed skies through the weekend.

A bit of snow is possible later Sunday into Monday ahead of colder temperatures slumping back into the region.

Today’s seasonal daytime high in Winnipeg is -9 °C while the seasonal overnight low is -18 °C.