Significant weather advisory

A significant weather advisory was a hazardous weather statement issued by certain Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public about thunderstorm activity below designated severe criteria for or not expected to produce severe weather. The title assigned to the advisory — titled "significant weather alert" or referenced by its originating product, "special weather statement" — varied by the issuing WFO.

Created in April 2002 as an unofficial special weather statement sub-product, the advisory was issued when trained storm spotters or Doppler weather radar indicate that a sub-severe thunderstorm is producing or will soon produce hail or strong winds below NWS-determined severe weather warning criteria. Should conditions favor intensification or severe weather approach the alerted area, a warning may be required. While intense lightning or rainfall caused by the thunderstorm did not merit an advisory on its own, the advisory may also have mentioned the occurrence or likelihood of such phenomena. The NWS ceased usage of the "significant weather advisory" titling in August 2021, although it continues to issue special weather statements for sub-severe thunderstorms when warranted through the agency's local Weather Forecast Offices (WFO).