Mild But Dreary Weather Continues

The weather pattern that has brought temperatures well above seasonal to Winnipeg[1] – despite the persistence of low cloud supplied by the outflow winds of a high pressure system to our southeast – will continue to pump warm Pacific air eastwards into the region for another couple days. By the end of the weekend, however, a cold front is set to push through bringing more seasonal temperatures back to the Prairies.

Friday
1°C / -2°C
Mainly cloudy
Saturay
3°C / -3°C
Mixed skies
Sunday
-1°C / -13°C
Mainly cloudy; slight chance of flurries

Winnipeg will see cloudy weather today as low cloud entrenched in the Red River Valley refuses to exit as southerly outflow winds continue to reinforce the low-level moisture trapped underneath the substantially warmer air just off the surface[2] that has spread over southern Manitoba.

The cloud will be accompanied by breezy southerly winds to 30-40km/h. The temperature will only climb to around 0 or +1°C today. Some clearing is possible later in the day as drier air begins pushing eastwards into the Dakotas and may work its way northwards in the flow. It’s far from certain, but we could see some breaks in the cloudy skies later today into the evening. Temperatures will drop to around -2°C tonight.

This Winnipeg forecast sounding – valid at 10AM CST Friday, December 12, 2014 – shows a thin layer of saturated air right at the surface which will continue to produce low-level cloud.
This Winnipeg forecast sounding – valid at 10AM CST Friday, December 12, 2014 – shows a thin layer of saturated air right at the surface which will continue to produce low-level cloud.

Saturday looks to bring mixed skies with a lot of uncertainty on exactly what we’ll see. Weather models want to clear things out fairly well and give us sunny skies with a high near 6°C. Unfortunately, I’m not entirely convinced that’s what will happen. The Red River Valley will sit on the cusp of where the return flow from the high pressure system meets drier air pushing in from the southwest. However, a low pressure system approaching from the west will likely back the winds slightly, tapping into the low-level moisture in the outflow winds from the high. Additionally, large-scale lift ahead of the low could also work to develop more low cloud ahead of the approaching cloud. So while the day may end up sunny, it seems a bit more likely we’ll see mixed skies or increasing cloud through the day. Due to that, I think the high will be closer to 3 or 4°C with temperatures dropping to around -3°C overnight under mainly cloudy skies.

Sunday will be a mainly cloudy day as a low pressure system passes to our south. Northwesterly winds will bring more seasonal Arctic air into the region through the day, limiting our daytime highs to -1°C with just a slight chance for some light flurries.

Through much of next week seasonal to slightly above seasonal temperatures are expect with no significant precipitation events in the forecast.


  1. Our daytime highs near -1°C are about 8°C above seasonal for this time of year.  ↩
  2. As shown in the figure mid-way through this post, while surface temperatures will struggle to climb just above 0°C, temperatures just 1.5km off the ground are nearly 17°C.  ↩

Brad

Brad lives in Winnipeg with his wife and two children and is the founder of A Weather Moment. He has loved weather from a very young age and has followed that passion through his life so far. He received a B.Sc. in Earth Sciences with Specialization in Atmospheric Sciences and is currently employed in the field of meteorology. You can find the author as WeatherInThePeg on Mastodon.

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