It won’t be long before we get our first snowstorm. When that occurs, you’ll hear me talking about bulletins issued by the National Weather Service. The most common are Winter Storm Watch, Winter Storm Warning and Winter Weather Advisory.

A Winter Storm Watch is issued when there is the potential for a winter storm, but before the path and consequences are certain. The NWS typically issues watches 12 to 48 hours in advance.

A Winter Storm Warning is issued when a winter storm is occurring or is imminent. They are usually issued when the forecast calls for 6 inches of snow or more in 12 hours or less. One may also be issued if 8 inches or more is expected over 24 hours. Just 3 to 6 inches of snow may trigger a warning if that snow occurs with winds of 25 to 34mph. Warnings may also be issued for lesser amounts of snow if it is expected to fall during rush hour. A mix of freezing rain and sleet with snow can also lead to a warning.

A Winter Weather Advisory is issued when the impact of a winter storm is expected to be lower than warning conditions. Advisories are issued for snow, sleet, freezing rain, or a mixture. Snow accumulations of 3 to 6 inches with winds less than 25mph will trigger an advisory. Advisories may also be issued for lesser amounts of snow if it is expected to fall during rush hour.