Issued when heavy snow, heavy freezing rain or sleet is expected OT occur. Winter storm warnings are usually issued 6 to 12 hours before the event is expected to begin.
Issued when hazardous winter weather is occurring, imminent or highly likely over part or all of the area. Hazardous winter weather includes but is not limited to heavy snow, blizzards, ice storms, freezing rain or drizzle and sleet.
As the winter weather event becomes more certain and imminent, a warning will be issued. The warning has the same criteria as the winter storm watch. If only one weather condition is expected, a warning for just that event will be issued. For example, only a heavy snowfall is forecast to occur so a Heavy Snow Warning would be issued.