Section 2: Advisories and Warnings

Definitions

The National Weather Service (NWS) is a good source for regional and national information of approaching adverse conditions. The NWS data and products form a national information database and infrastructure which can be used by other governmental agencies, the private sector, the public and the global community. The NWS system of advisories and warnings can be useful.
  1. Warning: A weather condition that is life threatening to those caught outdoors
  2. Advisory: A weather condition that is an inconvenience to people outdoors or can produce difficulty in travel
  3. Winter Storm Watch:
    • issued when conditions are favorable for the development of hazardous winter weather
    • these conditions may occur singularly, or in combination with others
    • usually issued 24 to 48 hours in advance.
  4. Winter Storm Warning
    • issued when life threatening winter weather conditions are imminent or very likely
    • includes the occurrence of combinations of snow, ice, wind and cold.
  5. Blizzard Warning
    • sustained wind or frequent gusts of 35 mph or more
    • considerable falling snow and blowing snow frequently reducing visibility to one-quarter mile or less
    • conditions last three hours or more.
  6. Winter Weather Advisory Issued for sleet, snow, freezing drizzle/rain or blowing snow
    • sleet accumulations are expected to be less than one half of an inch
    • snowfall of two to five inches in 12 hours
    • light accumulations of freezing drizzle or freezing rain
    • blowing snow intermittently reducing visibility to one quarter of a mile.