The new AVN/MRF MOS stations are arranged alphabetically by state abbreviation.
Within a state, the stations are listed alphabetically by ICAO call letters (4-character identifiers).
The list covers all 50 states, the District of Columbia, Puerto Rico, and Canada.
Several comments are important to interpreting the tables:
First, the observations were checked by considering whether temperature and dew point observations were available reliably. If a station never reported either of those elements, the station was considered to be non- reporting. Second, only data for the period of April 1997 through December 1998 were examined. Third, only the hours of 0, 3, 6, 9, 12, 15, 18, and 21Z were examined. Fourth, a station had to report at least 67% of the time at 4 or more of those hours to be considered reliable. Fifth, sometimes a station was considered to be full-time (F) if the reporting frequency was 67% and the analyst judged that the station was now reporting reliably. Finally, the availability of temperature or dew point observations is not a reliable indicator of the quality of the station observations for other elements, particularly, cloud cover, current weather, or precipitation amount. In fact, for the AVN/MRF MOS development initiated during the summer of 1999, many of the stations were eliminated from the developmental sample for these elements because the meteorologist judged that the quality or frequency of the reports was inadequate.
The AVN/MRF MOS system will be implemented for all of the sites indicated in the table, with the exception that only max/min temperature guidance will be available for the 21 Canadian sites and 16 sites in the western U.S.