Winter weather glossary (Plain language)
Meteorologists use technical terms during winter broadcasts that are not always obvious if you did not grow up around snow. Here is what each word means in plain language.
If you only do three things
- Freezing rain (liquid rain that freezes on contact into a sheet of ice) is far more dangerous than sleet (bouncy ice pellets) or snow.
- Black ice is transparent glaze ice on dark asphalt—it looks exactly like wet pavement.
- Wind chill measures how fast wind cools exposed living skin; it never lowers the temperature of inanimate objects like pipes or cars below the actual air temperature.
Winter terms from A to Z
- Black Ice: A thin, clear coating of glaze ice on roads and sidewalks that lets the dark pavement show through, making it nearly invisible.
- Blizzard: A storm with sustained winds or gusts of 35 mph (56 km/h) or higher and blowing snow that drops visibility to 1/4 mile or less for at least 3 hours.
- Flash Freeze: A rapid plunge in temperature below 32°F (0°C) that turns wet roads and slush into solid sheet ice within 15 to 30 minutes.
- Freezing Rain: Rain that falls as liquid water and freezes on contact with cold roads, trees, and power lines, creating a heavy glaze of ice.
- Frostbite: Freezing of the skin and underlying tissue, most often on fingers, toes, nose, ears, and cheeks. Skin turns numb, pale, and waxy.
- Frost Heave: An upward swelling of soil or pavement caused by freezing water expanding underground.
- Graupel ('Soft Hail' or 'Snow Pellets'): Tiny, fragile white balls of rime-coated snow that look like miniature Styrofoam pellets.
- Ice Dam: A ridge of ice that builds up along the lower edge of a roof, trapping melting snow behind it and forcing water under the roof shingles.
- Lake-Effect Snow: Narrow, intense bands of heavy snow formed when frigid air blows across the relatively warm, unfrozen waters of large lakes (can dump 2 to 4 inches of snow per hour).
- Nor'easter: A powerful coastal storm along the US East Coast with winds blowing from the northeast off the Atlantic Ocean, bringing heavy snow, wind, and coastal flooding.
- Polar Vortex: A large area of frigid low-pressure air circling the Arctic that occasionally wobbles southward, sending sub-zero air deep into North America or Europe.
- Sleet: Raindrops that freeze into small, hard, translucent ice pellets before hitting the ground. They bounce with a tapping sound.
- Slush: Partially melted snow mixed with water on the ground. Very heavy and freezes into rough, rutted ice overnight.
- Whiteout: Conditions where heavy blowing snow blends the sky and ground together so you cannot see the horizon or road edges more than a few feet ahead.
- Wind Chill: What the air temperature 'feels like' on exposed human skin when combined with wind speed.
Related guides
- Never seen snow before? Start here: Beginner guide to snow and cold weather.
- Use this site offline: How to save this guide on your phone.