National Weather Service Storm-based (polygon) Warnings

Abstract

On October 1, 2007 NOAA’s National Weather Service began a major service change. Short-term warnings for tornadoes, severe thunderstorms, flash floods, areal floods, and marine hazards have migrated from being issued for entire counties, parishes, or zones to those that are more geographically specific. The stormbased polygon system will make possible the warning of small portions of individual counties or adjoining counties, and as a result only warn that portion of the population that will be impacted by the storm.