Snow on the way – but how much reaches Calgary?

AFTERNOON UPDATE: So far, our speculation is on the right track. 

 

Of note; there are a pair of other models projecting for over ten centimetres. I'm not completely discounting that... but the pattern is still looking more likely that the system bypasses us for the heaviest snow.

There are few other changes to our temperature and condition outlooks. A few more overnights will reach the freezing mark. That's the extent!

 

MORNING EDITION: That was quite the run we had.

From yesterday’s data, we were just shy of eight degrees above our seasonal normal for the first 19 days of October (seasonal average being near 13 C, actual being 20.6 C so far).

The scales likely won’t fully balance for the last eleven days of the month; for that to happen, we’d need average highs I don’t much want to think about.

Today, we’ll experience a series of northerly gusts to kick things off, and from there, the cozy knits and thicker jackets replace the T-shirts and flip flops for the foreseeable future.

Calgary’s snowfall total is the ongoing, somewhat-unknown element at this time. Some models show a half a foot of snow; some that show flurries. So which one’s right?

Here’s the breakdown.

Albertans know that systems crossing those pesky Rockies have a lot of variability to them; we don’t have modeling technology that tracks it well. Looking for correlations across different models can be helpful; and so can soundings, like the one below from Meteocentre:

(Skip the science to the next paragraph, as you please!) The red and blue lines on here are our temperature and dewpoint temperature lines. Them being bound together through the mid-layer of our atmosphere (the ‘500’ in black on the left side of the chart) in a freezing environment means we’re looking at snow. However, our surface temperature likely doesn’t support that snow sticking around, at least at first; snowflakes hitting surfaces don’t like positive temperatures all that much.

At this time, we’re likely facing those big, wet, dense snowflakes. They’ll fall at a decent rate through the late hours, and then we have two scenarios:

-          The way this storm tilts as it crosses the Rockies pushes a layer in that coats the grass and makes the roads a wet mess

-          The storm tilts even heavier and we get a full coat, making the roads a wet mess

…you may notice some common ground there. Wet snow usually has a lesser accumulation because it’s denser and sits heavier. If I’m pressed into making a call on the snowfall total, my lean at this time is between two and four centimetres; the isolated models with a double-digit snowfall total require a very specific track for this system that causes it to sustain through the majority of the day, and I’m not sold on it yet.

Oh, and the rest of the forecast is cool and drab. See below and stay safe out there. Dare I say… stay frosty?

Your five day forecast:

Thursday

•  Evening: mainly clear, low 3 C

Friday

• Mainly cloudy, scattered showers
• Daytime high: 9 C
• Evening: mostly cloudy, overnight showers becoming snow showers, low 0 C

Saturday

• Snow showers; mainly cloudy; 2-4 cm
• Daytime high: 3 C
• Evening: chance of mixed precipitation, low -1 C

Sunday

• Partly cloudy
• Daytime high: 4 C
• Evening: some cloud, low 0 C

Monday

• Partly cloudy
• Daytime high: 10 C
• Evening: some cloud, low 1 C

Tuesday

• Mainly sunny
• Daytime high: 9 C
• Evening: some cloud, low -1 C

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