snowstorms

Snowstorms are weather events characterized by the rapid accumulation of snow on the ground, typically accompanied by reduced visibility and sometimes strong winds. They arise when cold air interacts with moist air, often within extra-tropical cyclones, frontal systems, or lake-effect processes. Snowstorms differ from blizzards, which require sustained winds of at least 35 mph (56 km/h) and visibility reduced to a quarter mile or less for three hours or more.

Types and formation: Lake-effect snowstorms form when cold air passes over relatively warm lakes, producing narrow bands of heavy snowfall. Nor'easters and other frontal snowstorms develop from large low-pressure systems bringing air masses of different temperatures together. Snowstorms may produce heavy snowfall rates for hours, or prolonged accumulation over days in persistent winter weather patterns.

Impacts and hazards: Snow accumulation can disrupt transportation, damage infrastructure, and trigger power outages, roof collapses, and hazardous travel conditions. Icing, drifting snow, and reduced daylight can compound risk. Economic costs arise from delays, emergency responses, and required snow removal.

Forecasting and warnings: Meteorologists use surface and upper-air observations, radar, and computer models to predict snowfall and wind. Public warnings include winter storm warnings, winter weather advisories, and blizzard warnings, guiding school closures, travel restrictions, and preparations.

Regions and history: Snowstorms most affect mid- to high-latitude regions, especially areas near large landmasses or lakes. Notable events include the Great Blizzard of 1888 in the United States, the 1978 Northeastern Blizzard, and the Storm of the Century in 1993.