CALGARY — Fire weather warnings now extend for our American neighbours across Idaho and out to South Dakota. This is part and parcel to our upper-air pattern’s largely zonal flow (west-to-east-moving wind), pushing a wide array of features, including dry air and smoke, from the west coast across continental North America in the coming days.
Because smoke is primarily guided along by wind at 500mb, or halfway along the atmosphere, the vast majority of the smoke moving east of the Rockies is “aloft” – it’s above us, with the potential for some to settle as the day rolls along. While the effects above us might appear dire:
…the surface impact will be less-so. Using the NASA satellite top-down view shows the entire picture through the entire atmosphere, which is not an accurate reading, since a good portion of these particulates are going to be working along the ground. That said, below are the 00-24 and 24-48 hour outlooks as issued by Environment Canada’s “Firework” model at 6 pm Sunday:
Today and tomorrow, our atmosphere is not buoyant enough to completely dismiss smoke particles from reaching the surface. As the trail of carbon passes over us, it will act as a large, ominous “rain cloud”, precipitating particles into our lower atmosphere as the Firework model suggests.
Cooler temperatures are on the way including a cold front tomorrow evening. That cold air will further reduce our buoyancy for tomorrow evening, which could in turn increase our smoke.
An Arctic high pressure air mass cycling through Saskatchewan and Manitoba could put up a “wall” of cold air, keeping us entrenched beneath smoke beyond Sept. 16.
Here’s a quote from our Aug. 21 article:
“To speak on the 2.5pm Avg (ug/m3) that this chart (Firework) tracks: it’s keeping a watch on the amount of particulate matter of a size at 2.5 microns or smaller per cubic meter of air. For reference: the dust particles that float around our homes are 10 microns thick. Human hair is 50-70 microns thick. These are tiny, tiny particles, which can have an impact as they enter one’s respiratory tract, causing irritation to the lungs. Shortness of breath, coughing, sneezing, and runny nose are also common signs in these conditions that one should spend some time indoors.”
Here’s the five-day forecast:
- Mainly cloudy, smoky
- Daytime high: 14C
- Evening: clear, low 7C
- Mainly cloudy, smoky, late-day cold front brings showers
- Daytime high: 15C
- Evening: some showers, low 5C
- Showers clear early, then “mainly sunny’ with some smoke
- Daytime high: 16C
- Evening: clear, low 6C
- Mainly cloudy
- Daytime high: 12C
- Evening: clear, low 7C
- Mainly sunny
- Daytime high: 17C
- Evening: clear, low 9C
Tab snapped a lovely image at Griffith Woods Park for the pic of the day.
You can submit your weather photos here.