Environmental Broadcast circuits that are keyed to the AWN. FNMOD Tinker also provides guidance on AWN data formats and can assist with preparing request   messages   for   AWN   products.   Detailed information  on  the  AWN  can  be  obtained  from the FNMOD Tinker homepage at http://www.fnmoc.navy.mil/~tinker/. AFMEDS.—The data network used to support Air Force,  Navy,  and  Marine  Corps  meteorological facilities  within  the  United  States  is  called  the Continental  United  States  (COWS)  Meteorological Data System, or COMEDS. In the early 1970's, the service  was  expanded  to  include  the  European Meteorological Data System (EURMEDS), the Pacific Meteorological Data System (PACMEDS), the Atlantic Meteorological Data System (ALTMEDS), and an Alaskan Meteorological Data System (AKMEDS). These  services  are  subsystems  of  the  Air  Force Meteorological  Data  System,  or  AFMEDS.  Most  of these dedicated landline circuits will be phased out by early next century as the NIPRNET becomes the primary method of transmitting AWN data. Software known as the Message Format Transmitter (MFT) module will be incorporated into the Meteorological and  Oceanographic  (METOC)  Interactive  Data  Display System  (MIDDS)  to  complete  this  changeover. However, the actual AWN data formats will not change. Ships will continue to receive AWN data via the Fleet Environmental  Broadcast,  which  is  discussed  later  in the  chapter. ARQ   Requests.—Incoming     environmental information is stored in the AWN computers in files identified  with  a  MANOP  heading.  (MANOP  headings will be discussed in more detail shortly). As each observation or product is received in the computer, the data is forwarded to all units that have listed that particular MANOP as part of their data requirements. Additionally, any activity connected to the system may request individual products that are not on their data requirements  list  by  a  process  called  Automatic Response to Query, or ARQ. Individual activities may also use the system to transfer specific support products from a forecast activity, such as a detachment, to any other activity on the system. MANOP Headings.—The    use    of    MANOP headings is the key to data retrieval from the system. MANOP  headings  conform  to  WMO  product identification guidelines as well as to the International Civil  Aviation  Organization  (ICAO)  guidelines  for station identification. Every MANOP must follow the general  format TTAA(ii)  CCCC  YYGGgg  (mod) where TT AA ii CCCC YYGGgg Mod is  the  data  content  identifier—a  two- letter code for the type of data contained in  the  bulletin  or  message; is the Geographical designator—a two- letter code for the region covered by the data  in  the  bulletin  or  message; is a two-digit series number assigned to products containing similar data for similar areas, and issued by the same originating  station; is the four-letter ICAO station identifier for the station originating or compiling the  information  in  the  bulletin; is the UTC date-time group (DTG) of the  information  within  the  bulletin  or message, with YY as the day, GG as the hour, and gg as the minutes; and is   a   modification   indicator-an abbreviation showing that a change has occurred  in  an  otherwise  routinely scheduled message. Mod indicators are "RTD"  (routine  delayed)  and  "COR" (correction). Each product entered in the system must contain the proper MANOP header before being entered into the system.  However,  transmissions  of  some  routine products, such as standard military station weather observations and terminal aerodrome forecasts (TAFs) are   normally   sent   through   the   system   without MANOPs. Instead, they are grouped into a collective by the system, and then assigned a MANOP by the AWN computer. Appendix II provides a breakdown of the various MANOP data type identifiers (TT)  and  geographical designators (AA) used within the system. A complete listing of available data in the AWN system can be obtained from the AFWA Detachment 7, Tinker AFB website:  http://137.240.101.95,  and  the  FNMOD Tinker  website. NOTAMS.—The AWN also provides communications for the worldwide military NOTAM system.  The  Air  Force  Central  NOTAM  Facility (AFCNF) in Washington, D.C. collects and retransmits NOTAMs from all military airfields as well as civil aviation NOTAMs from the FAA NOTAM facility in Atlanta, Georgia. NOTAMs report items of interest to 1-12