Snow this morning, wind this afternoon for Calgary

CALGARY -

Your bottom line up front: Avoid travel where you can.

Damaging wind is possible south of Calgary. Heavy snow is possible north of us. Calgary's full Stealers Wheel, with some snow, some wind, and parameters aligned for no watch, warning, or statement at this time.

Here we go:

The jet is south of us. We're in a zone where Pacific moisture is hurtling off the foothills, which paints this picture of warnings for BC:

Extraordinarily heavy rain has generated terrible conditions, including evacuation orders:

NOTICE TO RESIDENTS: If you are in the outlined area, South of Coldwater Avenue and East of Voght Street, please evacuate immediately. pic.twitter.com/wPxV6RcQLG

— City of Merritt (@CityofMerritt) November 15, 2021

On our side of the boundary, we get this picture:

Moisture shoves across the boundary, with portions of the mountain parks cranking the dial into the 30 to 40 centimetre range along Highway 93 from Jasper straight down to Lake Louise. This adds to snow that began yesterday. Upward of 60 cm may result from this band.

Let's talk diminishing returns.

As this band pushes off the southern foothills, snowfall amounts will drop off drastically. Calgary's initial estimates of five to 10 cm have fallen off, assisted by milder temperatures and a slight adjustment to the formation zone of the Clipper. We'll still see a range of two to five cm, but this afternoon that changes to melting weather; the southern foothills are completely inundated by wind warnings as the Clipper rapidly plunges our pressure, which will lead off the foothills with 110 km/h gust potential, before "dying down" to 100 km/h. This will happen into the afternoon as the low forms. Calgary is too far north for this warning (so is Okotoks), but we may top the 60 km/h marker here. So, morning snow, afternoon chinook, overnight snow. Sure. Why not.

North along the QEII Highway snow builds up yet again, with 10 to 20 cm possible through the northern face of the forming Clipper, and special weather statements are in effect for Drayton Valley, where temperatures will hit a range for potential freezing rain this afternoon. Snowfall to the west of Calgary will top the 10 cm marker in higher elevations.

As with all Alberta Clippers, it then moves along rapidly. Tomorrow morning, another lick of snow may shove off the foothills, generating an additional centimetre or two (and more in the foothills) for Calgary. By dinnertime tomorrow, the system will be in Manitoba, which paints the following:

Saskatchewan's winter storm warnings are effectively copycats of last week's Clipper; an additional 20 to 35 cm is on the way. The special weather statements in Manitoba and northern Ontario will likely be replaced with snowfall warnings later today.

YOUR FIVE-DAY FORECAST

Today:

• Morning snow, then SW gusts in the 60s
• Daytime high: 7 C
• Evening: some cloud, a chance of flurries, low -2 C

Tuesday:

• Mainly cloudy, NW gusts in the 60s
• Daytime high: -1 C
• Evening: mainly clear, low -9 C

Wednesday:

• Mainly sunny
• Daytime high: 0 C
• Evening: clear, low -6 C

Thursday:

• Partly cloudy
• Daytime high: 5 C
• Evening: some cloud, low -3 C

Friday:

• Partly cloudy
• Daytime high: 3 C
• Evening: some cloud, low -6 C

A quick pic of the day: Cathy sent this in, citing it from a few weeks ago: these are Kelvin Helmholtz waves! They're generated by differential wind shear - two layers of the atmosphere moving at different speeds through a moist layer.

You can submit your photos here, email me here, or tweet them over!