Extreme Cold on The Way Out

A clipper system tracking through Southern Manitoba today will bring near-normal temperatures and a very slight chance of a flurry through the early afternoon. Once the system passes through, we’re going to settle into a fairly stable pattern as a dome of cold air settles over Hudson Bay, keeping us in a benign but cool pattern for the remainder of the week.

Wednesday
-11°C / -25°C
Cloudy; a marginal chance of midday flurries. Clearing later in the day.

Thursday
-20°C / -25°C
Mainly sunny.

Friday
-18°C / -22°C
A few clouds.

Today will bring relatively mild weather as temperatures climb up to -11°C or so thanks to a weak clipper system tracking through Central Manitoba that is dragging some warmer air with it as it pushes through. We’ll see mainly cloudy conditions through the morning and early afternoon with clouds then clearing out late in the afternoon or early this evening. There’s a very slight chance of a flurry or two starting midday and through the early afternoon, but the risk is very slight at that. Any organized snowfall should remain to our north and to our east, but even there only around 2cm is expected. By mid-afternoon there will be essentially no threat of snow and the clearing will begin.

This 700mb temperature chart for Saturday evening shows the dome of cold Arctic air set to settle over Hudson Bay.
This 700mb temperature chart for Saturday evening shows the dome of cold Arctic air set to settle over Hudson Bay.

As the clipper system pushes off into Ontario, cooler air will begin filtering into Manitoba. We’ll see temperatures drop to around -25°C tonight with a modest recovery to around -20°C tomorrow under mainly sunny skies. The temperature will drop to around -25°C once again tomorrow night under clear skies. Friday looks to climb a little bit warmer to around -18°C with some afternoon clouds as a very weak disturbance whips across the province. Slightly warmer air aloft will bump up our overnight low a few degrees to around -22°C or so under clear skies once again.

More of the same (perhaps cooling off a little) is in store for the weekend. No significant snowfall events[1], in Winnipeg or the Red River Valley, are expected right through to the end of next week.


  1. “Significant” in this case meaning 2cm or more.  ↩

Quiet, Mild Weekend Ahead

A very benign weather pattern will move over Southern Manitoba as a ridge of high pressure builds into Manitoba bringing increasingly sunny skies and temperatures slowly trying to climb towards seasonal.

Friday

21°C / 9°C
A mix of sun & cloud.
Saturday

24°C / 11°C
Mainly sunny.
Sunday

24°C / 11°C
Mainly sunny

We’ll see a mix of sun and cloud today as daytime heating is able to produce some shallow convection, but there won’t be enough instability remaining to produce any precipitation as subsidence moves in ahead of the approaching ridge of high pressure. Today will be our coolest day with temperatures only climbing into the low 20’s. Tonight will be quite cool with our temperature dropping just under 10°C by tomorrow morning.

Tomorrow we’ll be under the influence of the high and we’ll see mainly sunny skies as temperatures climb back towards more seasonal highs – which for this time is around 26°C – of around 24°C. Sunday will be nearly a carbon copy of Saturday with a high near 24°C and an overnight low of around 11°C.

Next Week

We’ll start next week with a fairly nice day on holiday Monday with highs in the mid–20’s under a mix of sun and cloud.

NAEFS 8-14 Temperature Anomaly Outlook produced at 12Z August 1, 2013

NAEFS 8–14 Temperature Anomaly Outlook produced at 12Z August 1, 2013. Areas in red indicate above-normal temperatures, while areas in blue indicate below-normal temperatures, expected for the week after next (8–14 days from now).

The rest of the week looks to be fairly steady temperature-wise, however some models are hinting at a system that may bring some showers or thunderstorms to the region mid-week. No significant warm-up is in sight as a persistent vortex continues to redevelop over northern Ontario and Hudson Bay, keeping a persistent northwesterly flow over the eastern Prairies.

Slightly Cool Weather Continues

A persistent low-pressure centre over Hudson Bay will continue to bring cool nights and mild, but not hot, summer days to Winnipeg as it blocks the jet stream from pushing northwards into the southern Prairies.

Wednesday

23°C / 13°C
Partly cloudy with a slight chance of late-day showers.
Thursday

22°C / 12°C
Partly cloudy with a tiny chance of late-day showers.
Friday

22°C / 10°C
Partly cloudy.

The next few days will see very little variation as cooler air ever so slowly slumps southwards into the Southern Prairies. We’ll see a chance of late-day showers in the Red River Valley today and tomorrow, however the chance is pretty minuscule and by no means will the showers be widespread. Temperatures will climb into the low 20’s for highs and start around 13°C for overnight lows and drop towards the 10°C mark by the end of the week. By friday the chance for showers drops off and we’ll likely just see a few clouds in the afternoon.

No Heat on the Horizon

Looking ahead to the long-range it doesn’t appear we’ll see any hot summer weather headed our way for the next 7–10 days. The low that’s keeping us cool is going to stick around for a couple days before backing up to the west, grabbing another batch of cool Arctic air and then diving southwards towards Southern Manitoba…at least, that’s how it looks now. It seems somewhat reasonable as most models have locked into a fairly consistent west-coast ridge and mid-continental toughing pattern for the next while.

Personally, I love the warm but not hot days and cool nights, although given our long-delayed spring, I’m not going to complain if nature can throw another blast of hot and humid weather our way again.

Sunny Weekend Ahead

Sunny weather will dominate the Red River Valley as a ridge of high pressure moves into Manitoba. Temperatures will be below-normal through the next 3 days as we remain entrenched in a cooler air mass originating from the north while the jet stream remains locked up in the United States.

Friday

20°C / 7°C
Mainly sunny.
Saturday

22°C / 11°C
Mainly sunny.
Sunday

24°C / 13°C
Mainly sunny.

Temperatures will slowly climb back towards the mid-20’s by the end of the weekend, while overnight lows will start at an extremely unseasonably cool 7 or 8°C and warm to around 13°C by Sunday night. Skies will be mainly sunny the next several days with no precipitation in sight.