The wildfire situation is ongoing. Below, a New York Times map...
Following the situation in real time:
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Copilot:
How do wind currents usually travel across North America?
The short answer: North America’s winds usually move west → east, but the pattern shifts with the seasons and altitude. Here’s the clear, structured breakdown you like, Louise.
🌎 The dominant pattern: West‑to‑East flow
Across most of the continent, the prevailing winds are called the westerlies. They blow:
From the Pacific toward the interior
Across Canada and the northern U.S.
Toward the Atlantic
This west‑to‑east flow is strongest at mid‑latitudes (roughly from the U.S. border up through southern Canada), which is exactly where you live in Québec.
🌀 Why this happens
Two big systems shape North American wind:
1. The Jet Stream
A fast river of air high above the continent that steers weather systems.
It usually runs west → east, but it wiggles:
Dips south bring cold air into the U.S.
Bends north bring warm air into Canada
Strong dips can pull wildfire smoke thousands of kilometres
2. Hadley & Ferrel cells
Large atmospheric circulation cells that create the westerlies at our latitude.
🍁 Seasonal differences (Québec & Eastern Canada)
Summer
Winds still mostly west → east
But warm‑season systems can pull air north → south or south → north depending on storm tracks
Wildfire smoke often travels from Western Canada → Eastern Canada → U.S. Northeast
Autumn & Winter
Stronger west → east flow
More frequent northwest winds behind cold fronts
Occasional northeasterly winds during coastal storms (Nor’easters)
Spring
Highly variable
Jet stream shifts northward
More mixing of Arctic and subtropical air
🌬️ Local patterns you feel in St‑Jean‑sur‑Richelieu
Your region often gets:
Southwest winds bringing warm, humid air
Northwest winds after cold fronts (clear, crisp air)
Northeast winds during coastal storms
West winds during typical fair‑weather days
These align with the broader continental flow.
🔥 Why this matters for smoke maps
Smoke transport follows the same rules:
Western wildfires → smoke carried east
Prairie fires → smoke into Ontario/Québec
Jet stream dips → smoke pulled deep into the U.S.
Jet stream ridges → smoke pushed north into the Arctic
This is exactly why the map you found showed smoke sweeping across the continent.
If you want, I can explain how smoke from a specific region (e.g., Alberta, B.C., Northwest Territories) typically travels toward Québec, or how to read smoke‑forecast models like HRRR‑Smoke.
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