Communicating High Resolution Warning Information using National Weather Service Phenomena Based Hazard Grids

National Weather Service currently uses a combination of traditional text and graphic products limited to geo political counties or climatological based zones for large scale, long fused warnings. In the Western United States, the areal coverage of those counties or zones can exceed thousands to even tens of thousands of square miles. Many of the phenomena triggering those warnings are influenced by or limited to certain terrain or elevations within those descriptive areas. This leads to significant over warning of events, much like the over warning in the severe weather program before the use of polygons. By using a combination of high resolution mapping displays such as Google Maps and 2.5 KM Hazard Grids outlining the warned phenomena, National Weather Service Forecasters can provide more detail warning information to Emergency Mangers and the general public. Higher resolution warning information using Phenomena Based Hazard Grids has the potential to differentiate impacted areas such as transportation corridors, land versus marine environments, or specific elevation sensitive eco systems.