CAP (Common Alerting Protocol) is a XML based messaging protocol that is the standard for all alerting messages across North America and beyond. The CAP message contains information such as the originating agency, the intended recipients (e.g. general public, first responders, law enforcement), the degree of severity, the target area of the message and the alert message itself. To choose a mapping location, click on the circle next to the city:
| Target Area | Event | Area Descriptor |
View XML |
| Anaheim | Earthquake | Circle | View XML |
| Chicago | Thunderstorm | Geocode | View XML |
| Dallas | Amber Alert | Circle | View XML |
| SW Kansas | Snow Advisory | Geocode | View XML |
| New York City | Terrorist Alert | Polygon | View XML |
| Miami | Hurricane | Geocode | View XML |
| Mississippi River | Flood Alert | Polygon | View XML |
| Ohio-Pennsylvania | Tornado Warning | Polygon | View XML |
| Oregon-California | Tsunami | Polygon | View XML |
| Washington DC | Terrorist Alert | Circle | View XML |
Target areas are defined in three different ways; geocodes, circles and polygons. Geocodes are made up of a 5 digit number (FIPS code) which consists of 2 state digits and 3 county digits so that all 3140 counties and county equivalents across the U.S. have a unique code. The circle is defined by a pair of numbers indicating latitude and longitude followed by a number indicating the radius in kilometers. Last, the polygon is defined by a list of latitude and longitude pairs for each point and an additional "closing" point that is identical to the first point in the list.