This application presents a browsable archive of SPC issued tornado and severe thunderstorm watches. Each sequential watch is assigned a numeric ID, which uniquely identifies a watch for each year. Up until 2006, the polygon was the valid area of the watch. Since then, the valid area is issued by county and marine zone.
Initial Watch Box and Watch By County Outline
Local Storm Reports:
Watch Polygon (KML):
<MultiGeometry><Polygon><outerBoundaryIs><LinearRing><coordinates>-87.010000000000005,39.060000000000002 -82.359999999999999,40.469999999999999 -82.359999999999999,39.18 -87.010000000000005,37.75 -87.010000000000005,39.060000000000002</coordinates></LinearRing></outerBoundaryIs></Polygon></MultiGeometry>
Watch Polygon (GeoJSON):