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4.2.6.1 WMO Text Products

The entire WMO message, including the start and end lines, is often called the WMO "bulletin." The bulletin structure contains the WMO Abbreviated Heading Line, sometimes called the "product ID," or more often the "header," and the body often called the "text" of the message.

The Product Header Line Components

The AWIPS Product Identifier is composed of two lines, the WMO Abbreviated Heading Line in the first row and the AWIPS Identifier (AI) Line in the second row.

Each component of this Abbreviated Heading Line is defined below.

• T1T2: Data type and/or form designators

- T1: This is an alpha character that designates the general code form of the contents of the bulletin. Refer to WMO Manual 386 Table A in the following web site for detailed information: http://www.nws.noaa.gov/tg/table.html

- T2: This is another alpha character that designates the data type. Its definition depends on the T1 designator in Table A, and can be found in Tables B1 through B6 from the WMO Manual.

A useful cross-reference list between AFOS PILs "NNN" of the CCCNNNXXX used to identify products in the AFOS system and the WMO abbreviated heading "TT" groups can be found at http://www.nws.noaa.gov/datamgmt/x_ref/xr04_X_ref_by_NNN.html

• A1A2: Geographical area and/or data type designators

- A1: A1 is taken from WMO Manual 386 tables C1 through C6 depending on the T1 designator in Table A. It is an alpha character that defines the geographical area the text of the bulletin covers.

- A2: This alpha character designates the geographical area, or may define the forecast period. It is taken from WMO Manual Tables C1 through C5 depending on the T1 in Table A.

- ii: These two numbers are used to differentiate between two or more bulletins that contain data in the same code, originate from the same geographical area, and have the same originating center. The following sets of "ii" numbers are used for indicating the bulletins for global, interregional, regional, and national distribution. The national distribution may have further definition as in the case of the U.S. National Weather Service.

Refer to WMO Manual 386, paragraph 2.3.2.2, or from Table D1 or D2 depending on the T1 designator in Table A.

• CCCC: This four-letter ID is the international location identification of the processing center that generated the bulletin. Once the bulletin has been originated or compiled, the CCCC must not be changed even if the bulletin in question has to be edited at another center.

The NWS also has some special CCCC practices which are used to further define products sources within the National Centers for Environmental Prediction (NCEP). Following International Civil Aviation Organization (ICAO) standards, the first character is "K" for the CONUS offices, followed by the three-letter FAA identifier. For offices outside the CONUS, the first two characters are PA for Alaska, PH for Hawaii, and TJ for Puerto Rico followed by an additional two characters. The national centers use a national practice form of the K<CCC> for CCC.

Note: The three-letter AFOS node identifier CCC is no longer valid in the AWIPS environment and will not appear in the AWIPS headings.

• YYGGgg: This is the International Date-Time Group, and is defined as follows:

- YY: This pair of numbers identifies the day of the month (01, 04, 10, etc.).

- GGgg: This is the Hour-Minute Group. For bulletins containing meteorological reports intended for standard observation times, the time is the standard UTC observation time. For aerodrome, route and area (aeronautical) forecasts, the full UTC hour (the last two digits are 00) preceding the transmission time is used. For other forecasts and analyses, use the standard UTC observation time on which the forecast or analysis is based. For other messages, use the UTC time of compilation to the nearest minute.

- BBB: This three-letter Indicator Group is used to define the type of message being transmitted, whether it be a correction, an amendment, a delayed transmission, or a normal transmission. Refer to Section 4.4, Editing Text Products, for more information.

• NNNxxx: This is the AWIPS Identifier (AI) Line and is comprised of four to six characters of the AFOS PIL without the CCC.

The one to three character xxx (product designator) is identical to the AFOS xxx. If the xxx is less than three characters, the character(s) are left justified and filled with blanks to complete the three-character field. After the transition from AFOS is complete, the number of allowable characters of the product designator may be increased if required (e.g., to accommodate five-character product designators of sites). The AWIPS software will be flexible to allow future expansion in the number of characters in the product designator.

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