From Glossary of Meteorology


  1. A disturbed state of Earth's atmosphere, which can manifest itself in temperature, humidity, pressure, wind velocity, cloud cover, lightning, and precipitation. Storms are organized disturbances that range in size from meters to a few kilometers (microscale, e.g., tornadoes), to a few to several hundred kilometers (mesoscale, e.g., mesoscale convective systems), to many hundreds of kilometers (synoptic, e.g., extratropical cyclones).

    Inclement and potentially destructive weather is often implied with a storm; threats can include heavy precipitation, flash flooding/river flooding, and high winds. From a local and special-interest viewpoint, a storm is a transient occurrence identified by its most destructive or spectacular aspect(s). In this manner we speak of rainstorms, windstorms, hailstorms, snowstorms, etc. Notable special cases are blizzards, icestorms, sandstorms, and duststorms.

  2. For a hydrology-specific application, see design storm.

  3. For a space weather–specific application application, see magnetic storm.

  4. (Also called storm wind, violent storm.) In the Beaufort wind scale, a wind with a speed from 56 to 63 knots (64 to 72 mph, ~29 to 32 m s−1) or Beaufort number 11 (force 11).

Term edited 1 March 2021.