WMO headers provide meteorological product identification fort he purposes of transmission and communication handling. 

The first line of a WMO header consist of two parts:

• Data Designators  - Provide information on data types, and broad geographical areas.

• Location Indicators  (CCCC) - Provide information on the station originating or compiling the product.

For this product transition, every product will have a second line as part of the WMO header is called a AWIPS Identifier.   The AWIPS Identifier consists of two parts:

• Category Indicator (NNN) - an abbreviation for a specific product type (eg. TOR = tornado warnings).

• Site/area Identifier (XXX) - This abbreviation indicates either the issuing weather forecast office (eg. CAE - Columbia, SC) , or area/site covered by product (eg. MD - Maryland or LGA - LaGuardia Airport).