Definition
A severe winter weather condition characterized by sustained winds of 35 knots or greater, accompanied by considerable falling or blowing snow that reduces visibility to less than one-quarter mile, lasting for at least three hours.
Plain English
A storm with strong winds and heavy or blowing snow that cuts visibility down to almost nothing for several hours.
Context Anchor
Seen in weather briefings and forecasts when planning winter flights.
Derivation
The word likely comes from early 19th-century American English, where 'blizzard' first meant a violent blow or sharp blast. It was later applied to fierce snowstorms in the U.S. Midwest. Knowing this helps reinforce that the defining feature is the wind, not just the snow.
Why Pilots Care
Triggers flight delays, cancellations, or diversions and creates severe icing and visibility hazards.
Grounding Statement
Picture snow being driven sideways so hard that the runway, horizon, and nearby buildings nearly disappear.
Intuition Check
Do not assume a blizzard means simply “a lot of snow.” In weather use, strong wind and very poor visibility are part of the meaning.
Example Sentence 1
The flight was cancelled when a blizzard moved across the airport, dropping visibility below a quarter mile.
Example Sentence 2
With visibility near zero in blowing snow, the crew diverted rather than attempt an approach during the blizzard.