Winter Season Terminology

Term Definition
Winter Storm Watch Adverse winter weather is possible in the watch area. 
Winter Storm Warning Hazardous winter weather will occur in the warning area.
Heavy Snow Snowfall accumulating to 6 inches or more in 12 hours; OR, 8 inches or more in 24 hours.
Blizzard The following conditions are expected to prevail for a period of three hours or longer:
  • sustained winds or frequent gusts to 35 mph or greater; and,
  • considerable falling and/or blowing snow (frequently reducing visibilities to less than 1/4 mile).
Ice Storm Heavy ice accumulations will cause extremely dangerous and damaging situations, such as icy roads and downed power lines.
Winter Weather Advisory Winter weather conditions (including snow, blowing snow, freezing rain, freezing drizzle) are expected to cause significant inconveniences.
Wind Chill Warning Issued when the wind chill is 35 below zero or colder. At minimum, a 10 mph wind should be occurring or forecast. 
Wind Chill Advisory Issued when the wind chill ranges from 20 below zero to 34 below zero...with a minimum of a 10 mph wind.
Freeze Warning Issued when surface temperatures are expected to be below freezing for a significant amount of time during the growing season.
Frost Advisory Issued when widespread frost is expected during the growing season...generally when temperatures in the lower to mid 30s, clear skies and light winds are forecast.
High Wind Warning Issued for non-convective wind gusts of 58 mph or greater; OR, sustained winds of 40 mph or greater expected to last one hour or longer.
Wind Advisory Issued for non-convective wind gusts of 45 mph or greater; OR, sustained winds of 30 mph or greater expected to last one hour or longer.

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