Snowstorms are a dime a dozen across Canada during the winter months. The most intense storms can grow into ferocious blizzards that cement their place in our collective memory, a legacy that lasts long after the last drifts have melted.
But what is it that turns a regular ol’ snowstorm into a bona fide blizzard?
INFOGRAPHIC: Your winter storm preparation checklist
Remember the 4-4-4 rule
Blizzards are severe snowstorms that produce near-whiteout conditions for a long period of time. But not all major or memorable snowstorms are true blizzards.
Surprisingly, neither the air temperature nor the amount of snow that falls have any bearing on whether you’ve got a blizzard on your hands. Meteorologists in Canada use Environment and Climate Change Canada’s (ECCC) 4-4-4 rule to gauge whether a snowstorm has crossed the line and become a full-blown blizzard.
Blizzard explainer: What is a blizzard – 4-4-4 rule
A storm needs to produce at least 40 km/h winds with blowing snow that reduces visibility to 400 metres or less for at least 4 consecutive hours. The rule changes slightly once you get north of the treeline, where the duration required for a true blizzard increases to 6 hours.
These are the nastiest conditions you can encounter in a snowstorm—a whiteout that makes it difficult to see more than a little ways in front of you, if at all.
Not all blizzards require snow actively falling from the sky, either. Folks on the Prairies are familiar with a phenomenon known as ground blizzards, which occur when intense winds severely reduce visibility simply by blowing around snow that’s already blanketing the ground.
How to stay safe in a blizzard
A blizzard is especially dangerous to motorists because it’s easy to get lost, stranded, or even crash in such treacherous conditions. If you absolutely can’t stay home during an intense storm, tell someone when and where you’re going.
Even attempting to walk to the mailbox in a blizzard is a risky proposition. It’s easy to get disoriented or lost in a whiteout, potentially leading to life-threatening issues like frostbite and hypothermia.
(Mark Robinson) whiteout conditions ontario december 23 2022
Make sure your electronic devices are fully charged before a storm arrives, and have several battery backups in case of extended power outages. Staying connected is critical during a dangerous storm.
Have a plan to stay warm whether you’re at home or on the road. Ensure that you have warm clothing, adequate footwear, and plenty of blankets on hand if needed.
Keep an emergency supply kit at home and in your vehicle. Each kit should have first-aid supplies, batteries, flashlights, candles, food, and water. Make sure you’ve got snow removal tools in your vehicle in case you get stuck.
WATCH: This is what you should have in your emergency kit this winter
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Photo used in header image submitted by Cynthia Nardone-De Palma.