Winter Weather Awareness: Terminology
This week, November 9-14th is Winter Weather Awareness week for Pennsylvania. The National Weather service will be issuing daily messages to help you prepare for the upcoming winter season.
Monday’s message describes the terminology used for winter weather. The following is the message from our partners at the National Weather Service in State College, PA.
Here are some terms which the National Weather Service uses to describe winter weather as well as the definitions of watches…
Warnings and advisories issued for winter weather events.
A Hazardous Weather Outlook is issued prior to a Winter Storm Watch:
The outlook is issued when forecasters believe winter storm conditions are possible. Outlooks are usually issued 3 to 5 days in advance of a winter storm.
In general a Winter Storm Watch alerts the public to the possibility of heavy snow, heavy freezing rain, or heavy sleet. Winter Storm Watches are usually issued 24 to 72 hours before the beginning of a winter storm. These events may occur separately or in combination. A Blizzard Watch is issued when blizzard conditions are possible in 24 to 72 hours.
Since watches are issued well in advance of the storm, there will be times when the storm does not materialize so they may be canceled.
On the other hand, a warning is issued when hazardous winter weather is imminent or has already begun. It is issued for conditions which pose a threat to life and property.
The following are the warning headlines issued for winter weather events:
A Winter Storm Warning is issued when hazardous winter weather in the form of heavy snow, heavy freezing rain, heavy sleet or any combination of heavy winter precipitation is imminent or occurring.
Winter Storm Warnings are usually issued 12 to 24 hours before the event is expected to begin.
A Blizzard Warning is issued for sustained or gusty winds of 35 mph or more and falling or blowing snow creating visibilities at or below one quarter mile. These conditions should persist for at least 3 hours.
An Ice Storm Warning is issued when significant ice is expected to accumulate on trees, powerlines and roads. An ice storm is a very dangerous storm, disrupting traffic and knocking down powerlines.
Prolonged power outages can occur, leaving people without power for up to a week or more.
A Lake Effect Snow Warning is issued when heavy lake effect snow is imminent or occurring.
A Wind Chill Warning is issued when wind chill temperatures are expected to be hazardous to life within several minutes of exposure, usually at temperatures below minus 25°F.
An advisory is issued for less serious weather conditions. Specific advisories will alert you to weather that would have a significant effect on motorists, outdoor activities, or public events.
The following are the advisory headlines issued for winter weather events:
A Winter Weather Advisory is issued for accumulations of snow, freezing rain, freezing drizzle, and sleet which will cause significant inconveniences, but if sufficient caution is exercised do not usually threaten life and property.
A Freezing Rain Advisory is issued for any accumulation of ice from freezing rain or freezing drizzle. It only takes a small amount of ice to make roads very treacherous.
A Lake Effect Snow Advisory is issued when accumulations of lake effect snow will cause significant inconvenience.
A Wind Chill Advisory is issued when wind chill temperatures are expected to be a significant inconvenience to life with prolonged exposure and, if caution is not exercised, could lead to hazardous exposure.
If you need timely information, you can get it on NOAA weather radio all hazards. We broadcast twenty four hours a day across all of Pennsylvania.