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NOAA's NATIONAL WEATHER SERVICE SAYS: KNOW YOUR WINTER WEATHER TERMS

With Old Man Winter just around the corner, the National Weather Service urges residents to keep abreast of local forecasts and warnings and familiarize themselves with key weather terminology.

Winter Storm Warning: Issued when a combination of heavy snow, heavy freezing rain, or heavy sleet is expected. Winter Storm Warnings are usually issued six to 24 hours before the event is expected to begin.

Winter Storm Watch: Alerts the public to the possibility of a blizzard, heavy snow, freezing rain, or heavy sleet. Winter Storm Watches are usually issued 12 to 36 hours before the beginning of a Winter Storm.

Winter Storm Outlook: Issued prior to a Winter Storm Watch. The Outlook is given when forecasters believe winter storm conditions are possible and are usually issued 48 to 60 hours in advance of a winter storm.

Blizzard Warning: Issued 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.

Lake Effect Snow Warning: Issued when lake effect snow is expected to occur. A Lake Effect Snow Advisory also cautions for the possibility of snow.

Wind Chill Warning: Issued when wind chill temperatures are expected to be less than 34 degrees below zero.

Wind Chill Advisory: Issued when wind chill temperatures are expected to be between 20 below and 34 degrees below zero.

Winter Weather Advisories: Issued for accumulations of snow, freezing rain, freezing drizzle, and sleet which will cause significant inconvenience and moderately dangerous conditions.

Dense Fog Advisory: Issued when fog will reduce visibility to 1/8 mile or less over a widespread area.

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

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: 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.

posted October 27, 1999