A blizzard is a severe snowstorm characterized by strong winds and low visibility. During a blizzard, heavy snowfall can accumulate quickly, making travel dangerous and sometimes impossible. The combination of wind and snow can create whiteout conditions, where it becomes hard to see anything beyond a few feet. Blizzards can occur in many regions, especially in areas like the Northern United States and Canada. They often happen during winter months when cold air meets moisture in the atmosphere. People are advised to stay indoors and prepare emergency supplies, as conditions can change rapidly and become life-threatening.