National Weather Service United States Department of Commerce

 
How do the various forms of winter precipitation develop when when temperatures at or above the surface dip below freezing?
Snow Sleet Freezing Rain
  • Flurries: Light snow falling for short durations.  No accumulation or light dusting is all that is expected.
  • Showers: Snow falling at varying intensities for brief periods of time.  Some accumulation is possible.
  • Squalls: Brief, intense snow showers accompanied by strong, gusty winds. Accumulation may be significant. 
  • Blowing Snow: Wind driven-snow that reduces visibility and causes significant drifting.  Blowing snow may be snow that is falling and/or loose snow on the
    ground that is picked up by the wind.
  • Blizzard: Winds over 35 mph with snow and blowing snow reducing visibility to near zero.
  • Rain drops that freeze into ice pellets before reaching the ground. Sleet usually bounces when hitting a surface and does not stick to objects.  However, it can accumulate like snow and cause a hazard to motorist.
  • Rain that falls onto a surface with a temperature below freezing.  This causes it to freeze to surfaces, such as trees, cars, and roads, forming a coating or glaze of ice.  Even small accumulations of ice can cause a significant hazard.
Snow Formation With Deep Cold Layer Sleet Formation With Shallow Warm Air Between Cold Layers Freezing Rain Formation With Deep Warm Layer Between Cold Layers