The National Weather Service issues hazardous weather watches as an advance notice that dangerous weather conditions are possible. Watches typically cover fairly large areas and are valid for several hours. The watch does not indicate dangerous weather is imminent or actually occurring.
The National Weather Service issues hazardous weather warnings as an urgent indication dangerous weather conditions are occurring or are about to occur.
Advisories are issued to address hazardous weather events which are not a direct threat to life and property, but which may result in damage or casualties if people actively put themselves in harm’s way. Advisories are issued for urban and small stream flooding, snow, freezing drizzle, and assorted winter weather conditions.