Winter Weather Terminology

Heavy Snow - Snow accumulating 4 inches or more in 12 hours or less, or 5 inches or more in 12-24 hours for locations east of the Blue Ridge. For those areas in the Blue Ridge and west, heavy snow is defined as 5 inches or more in 12 hours or less, or 6 inches or more in 12-24 hours.

Blizzard - Sustained winds or frequent gusts of 35 mph or greater and considerable falling and/or blowing snow frequently reducing the visibility to less than one-quarter of a mile. Such conditions must last for a period of 3 hours or more in order for the storm to be classified as a blizzard.

Freezing Rain/Freezing Drizzle - Freezing rain or freezing drizzle occurs when precipitation falls in liquid form, but freezes on impact with the ground or other objects when surface temperatures are below freezing. Freezing rain results in a coating of glaze ice on all exposed objects. Damage to trees and power lines will be greater when the freezing rain is accompanied by high winds.

Sleet - Sleet or ice pellets are solid grains of ice which form from the freezing of raindrops or the re-freezing of melted snowflakes. Sleet bounces upon hitting a hard surface.

Snow - The term ‘snow’, used in forecasts without a qualifier such as ‘intermittent’ or ‘occasional’ means that snow is expected to be steady and probably will continue for several hours without letup.

Flurries - Intermittent very light snow. No accumulation is expected.

Snow Showers - Intermittent snow falling at varying intensities. Minor accumulations are possible.

Snow Squalls - Intermittent snow falling at varying intensities, briefly reducing visibility to a quarter-mile or less. Total accumulations are generally light, but snowfall rates can be briefly extreme (1/2 inch in 15 minutes).

Winter Storm Watch - a Winter Storm Watch is issued to inform the public of the possibility of a combination of any of the following events: blizzard conditions, heavy snow, or significant and damaging accumulations of freezing rain or sleet. A watch usually gives 12 to 36 hours advance notice of the onset of winter weather conditions.

Winter Storm Warning - a Winter Storm Warning is issued when a mixture of heavy snow, freezing rain, freezing drizzle or sleet is occurring, is imminent, or is very likely. If the precipitation is only expected to fall as snow, a Heavy Snow Warning will be issued.

Ice Storm Warning - an Ice Storm Warning is issued when the only winter weather event expected is significant ice accumulation from freezing rain. Significant accumulations of ice will down trees and utility lines.


Blizzard Warning - a Blizzard Warning is issued when blizzard conditions are expected to last for three hours or more.

High Wind Warning - a High Wind Warning is issued when sustained winds of 40 mph or greater are expected to last for one hour or longer, or wind gusts of 58 mph or greater are expected for any duration. A High Wind Warning is issued when the winds are not associated with thunderstorms.

Wind Chill Warning - a Wind Chill Warning will be issued for dangerous or life threatening wind chills of 20 below zero or lower are expected, with a minimum wind of 5 mph.

Winter Weather Advisory - Winter Weather Advisories are issued for winter weather events, such as snow, sleet, and/or freezing rain that are hazardous, but not enough to warrant a warning.

Wind Chill Advisory - a Wind Chill Advisory is issued for expected wind chill values of 5 to 19 below zero, with a minimum wind of 5 mph.

Dense Fog Advisory - Dense Fog Advisories are issued when fog restricts visibility to one-quarter mile or less over a widespread area.

Wind Advisory - Wind Advisories are issued when sustained winds of 30 to 39 mph are
expected to last for one hour or more, or wind gusts of 45 to 57 mph are expected for any duration. Wind Advisories are issued for winds not associated with thunderstorms.