What Do Those Weather Warnings Mean?-Environmental Health & Safety - Carnegie Mellon University

Thursday, December 22, 2011

What Do Those Weather Warnings Mean?

The National Weather Service uses specific winter weather terms to ensure that people know what to expect in the coming days and hours.

A Winter Storm Watch means that severe winter conditions, such as heavy snow and/or ice, may affect us, but its occurrence, location and timing are still uncertain. A winter storm watch is issued to provide 12 to 36 hours notice of the possibility of severe winter weather. A winter storm watch is intended to provide enough lead time so those who need to set plans in motion can do so.

A watch is upgraded to a Winter Storm Warning when 4 or more inches of snow or sleet is expected in the next 12 hours, or 6 or more inches in 24 hours, or 1/4 inch or more of ice is expected. Winter Weather Advisories inform you that winter weather conditions are expected to cause significant inconveniences that may be hazardous. If caution is exercised, advisory situations should not become life-threatening.

A Blizzard Warning means that snow and strong winds will combine to produce a blinding snow (near zero visibility), deep drifts, and life-threatening wind chill. Be sure to listen carefully to the radio, television, and NOAA Weather Radio for the latest weather  information. For additional information, visit the Weather Service's Winter Weather Awareness web page at: http://www.weather.gov/om/winter.

(Reprinted from the National Weather Service)


By: James Gindlesperger, jg57@andrew.cmu.edu, 412-268-3760