Winter Weather Terms:

Winter Storm Outlook: Issued at least 48 hours in advance when there is a good chance for a winter storm event impacting the area.

Winter Storm Watch: Issued about 24-48 hours in advance when:

  • A substantial snow accumulation is likely, with the potential for that accumulation to reach or exceed 6 inches in 12 hours or 8 inches in 24 hours, and/or
  • An ice accumulation is likely, with the potential for that accumulation to reach or exceed 1/4 inch on exposed surfaces.

Winter Storm Warning: Issued when the following winter storm criteria are imminent or in progress:

  • A substantial snow accumulation is likely, with the potential for that accumulation to reach or exceed 6 inches in 12 hours or less, or 8 inches in 24 hours or less, and/or
  • An ice accumulation is likely, with the potential for that accumulation to reach or exceed 1/4 inch on exposed surfaces.

Blizzard Warning: Issued when the following winter storm criteria are imminent or in progress:
for sustained or gusty winds of 35 mph or more, and falling or blowing snow creating visibilities at or below 1/4 mile; these conditions should persist for at least three hours. Blizzard conditions are particularly heightened when cold temperatures combine with the wind to produce wind chills below zero.

Blowing Snow Advisory: Issued for blowing snow conditions producing frequently reduced visibilities of 1/4 mile or less with winds up to 34 mph.

Winter Weather Advisory: Issued when a combination of falling snow and freezing drizzle, freezing rain, or sleet will occur producing inconvenient or potentially hazardous winter conditions that are not severe enough to warrant a winter storm warning.

Wind Advisory: Issued anytime during the year when sustained winds will exceed 30 mph for more than 1 hour or any gusts greater than 45 mph are expected for any duration.

Wind Chill Warning: Issued when wind chill temperatures are expected to be less than 25°F degrees below zero for 3 hours or more, with a wind of at least 10 mph.

Wind Chill Advisory: Issued when wind chill temperatures are expected to be between 15°F and 24°F degrees below zero for 3 hours or more, with a wind of at least 10 mph.

Dense Fog Advisory: Issued when fog will reduce visibility to 1/4 mile or less over a widespread area.

Frost/Freeze Advisory: Issued when a frost or freeze will occur in the fall through October 31st (up to the point when a killing freeze has occurred), or after April 15th in the spring.

Snow Flurries: Light snow falling for short durations. No accumulation or light dusting is all that is expected.

Snow or Snow Showers: Snow falling at varying intensities for brief periods of time. Some accumulation is possible.

Snow Squalls: Brief, intense snow showers accompanied by strong, gusty winds. Accumulation may be significant. Snow squalls are best known in the Great Lakes region.

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 picked up by the wind.

Sleet: 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 motorists.

Freezing Rain: Measurable 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.

Freezing Drizzle: Drizzle 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 thin coating or glaze of ice. Even small accumulations of ice can cause a significant hazard.

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.