CALGARY — The week of “every day for itself” continues with an arctic wave of snow and a downtrend today, because of course it does. An arctic air mass is dropping in on us, and it’s expected to produce convective snow showers today that, when they start, won’t let up until Saturday morning.
Here’s a quick explainer on “convective” snow:
- The colder air is, the denser it is.
- Cold air is coming from the north today.
- It will move in and force the cooler air in its way to rise.
- When air rises, it cools.
- When it cools, it condenses (condensation).
- When it condenses enough, it precipitates.
Calgary’s in the unique position of having not just the rise-factor from this arctic air mass, but also from orographic lifting, or, air getting squeegeed (probably an actual meteorological term) against the Rockies. So, air is being forced to rise, jammed southward, then jammed against the Rockies along the way. This can produce heavy snow at times and severely hamper visibility, especially along the Nordegg-Kananaskis corridor and further south from there.
Calgary’s current saving grace comes in the form of the QPF, or Quantitative Precipitation Forecast; this asks the question: if every drop of moisture in the sky decided to drop like a stone, how wet would we get?
Today’s QPF is 2 mm. Yes, we’ll see additive precipitation migrating along this convective band, but it’s not going to break us. Five to 10 centimetres is expected in most areas around Calgary.
A quick hit on the rest: after that cold wave travels through, our Saturday calms it the heck down and just is. Partly cloudy. Cool. Moving on. Westerly wind is back in a big way Sunday and our forecast rallies, producing gusts that will likely top the 60 km/h range and billow along into Monday.
Here’s the five-day forecast:
- Afternoon snow showers, cooling
- Daytime high: -2 C*, downtrend!
- Evening: more snow, low -10 C
- AM flurries, then partly cloudy
- Daytime high: -6 C
- Evening: some cloud, low -8 C
- Partly cloudy
- Daytime high: 8 C
- Evening: some cloud, low -1 C
- Mainly sunny
- Daytime high: 6 C
- Evening: some flurries, low -8 C
- Mainly sunny
- Daytime high: 3 C
- Evening: some flurries, low -4 C
Today offers up a couple of beautiful shots!
Tony caught this herd of deer in Coutts…
…and Emily snapped a wonderful winter photo just south of Calgary!
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