This order prescribes aviation surface weather observing procedures and practices applicable to all FAA and FAA-contract personnel engaged in taking and reporting aviation surface observations, including Limited Aviation Weather Reporting Stations (LAWRS) personnel, Non-Federal Observation (NF-OBS) Program personnel, as well as United States Coast Guard (USCG) personnel as a component of the Department of Transportation (DOT). This order includes practices and procedures for both manual and automated observation locations. Also included are practices and procedures for augmentation of automated observations and backup information in the event of system failure, erroneous or non-representative data. These procedures and practices are intended to provide a framework for identifying meteorological phenomena of importance to aviation and reporting their occurrence.

This order is distributed at the division level in Washington; Air Traffic Service, Air Traffic System Requirements Service, Flight Standards Services, Integrated Product Team for Surveillance and Weather, regional Air Traffic Divisions, the FAA Academy, the Aeronautical Center, the USCG Elizabeth City Facility, the DOD, a standard distribution to all air traffic field offices and facilities, FAA-contract weather and contract tower facilities, and the National Weather Service (NWS).

Order 7900.5A, Surface Weather Observing - METAR, dated July 1, 1996, is canceled.

1-4.   EFFECTIVE DATE

This order is effective September 1, 2001.

This revision incorporates changes that have occurred since the order was last revised on July 1, 1996. Although there have been very few significant changes to the order, there were a sufficient number of editorial changes to justify a new version. This revision:

a.  Changes the office of primary responsibility.

b.  Provides additional information on Runway Visual Range (RVR).

c.  Provides additional information on Non-Federal Observations (NF-OBS).

d.  Provides new information on an ice accretion remark (soon to be available).

e.  Provides more detailed information on Service Standards.

Appendix A, Abbreviations and Acronyms, contains abbreviations and acronyms used within this order.

1-7.   RELATIONSHIP TO FMH-1 AND OTHER DOCUMENTS

a.  Federal Meteorological Handbook No. 1, Surface Weather Observations and Reports (FMH-1). FMH-1 prescribes surface weather observing standards applicable to all federal agencies engaged in taking and reporting surface aviation observations. FMH-1 also prescribes the standard reporting and coding procedures used in the surface aviation observation. Order 7900.5B prescribes the procedures and practices to be followed by FAA, FAA-contract and NF-OBS personnel for the observing, reporting, and coding of surface observations which meet the federal standards. A brief description of the NF-OBS program is provided in Appendix B, Non-Federal Observation (NF-OBS) Program. This order complements, but does not change, the standards contained in FMH-1.

b.  The NWS Observing Handbook No. 7, Surface Observations, (WSOH-7). WSOH-7 provides procedures and practices for NWS and NWS-contract personnel which are similar to those in this order.

c.  Automated Weather Observing Systems Handbooks. A partial listing of the applicable handbooks necessary to operate the various automated weather observing systems includes:

(1)  Federal Aviation Administration, Operator Instructions, Automated Weather Observing System (AWOS), August 1, 1994, U.S. Department of Transportation, Washington, D.C.

(2)  Federal Aviation Administration, ASOS Ready Reference Guide (latest versions).

a.  Applicability. Except for LAWRS, the procedures and practices in this order apply to all facilities which have the capability to comply with the stated procedure or practice. Some procedures and practices vary at LAWRS sites. These differences are indicated throughout the order where applicable. LAWRS observers shall comply with all the standard procedures and practices, except for these specifically indicated differences. Those sections which are not applicable to LAWRS are marked NA LAWRS in bold type after the section title. Similarly, sections which apply only to LAWRS are indicated with ONLY LAWRS. LAWRS requirements are excerpted in Appendix C, LAWRS Requirements. At an automated site ranked as Service Level C, the basic weather observing requirements are the same as a LAWRS observation. LAWRS observers are not required to back up the observation if measuring or observing equipment is not available.

b.  Conflicting Information. In case of conflicting information, the procedures and practices in this order take precedence. However, any applicable FAA air traffic orders take precedence over any procedures or practices in this order which are in conflict. Such conflicts should be brought to the attention of the originator of this order.

c.  Terminology. Throughout this order, the following terminology applies:

(1)  "Shall" indicates a procedure or practice which is mandatory at all applicable facilities.

(2)  "Should" indicates a procedure or practice which is recommended at all applicable facilities.

(3)  "May" indicates a procedure or practice which is optional.

(4)  "Will" indicates futurity; it is not a requirement to be applied to current practices.

d.  Unforeseen Requirements. No set of procedures and practices can cover all possibilities in weather observing. The observer shall use good judgment, adhering as closely as possible to this order, to describe phenomena not adequately covered by specific instructions. Suggestions for possible changes in procedures and practices to cover such situations may be made through appropriate channels.

e.  Designated Stations and Service Standards. Throughout this order the phrase "designated stations" appears. This refers to facilities that have been instructed by the FAA to perform a specified task that is not required to be performed at all facilities. In many cases, a facility may be designated to perform a specified task based on the service standards set for an airport. See Appendix D, Service Standards.

f.  Regional, Field Office and Facility Procedures. The procedures in this order are the minimum requirements. Needs at the regional and especially at the local level may dictate additional requirements. Regional or field offices may coordinate these additional requirements with the Flight Service Division, (ATP-300), although it is not required.

Employee participation in directive writing and upkeep activities is encouraged. Any user who finds a subject matter conflict, an error, obsolete information or who would like to make recommendations or suggestions, should notify ATP-300, in writing. FAA Form 1320-19, Directive Feedback Information, is available for this purpose. If clarification or correction is urgently needed, you may call ATP-300 for guidance, but you should also use the FAA Form 1320-19 as a follow-up to verbal conversation.

Changes, additions, deletions, and corrections will be issued as necessary. These changes will be issued by the Program Director, Air Traffic Operations Program, Attn: ATP-300, FAA.

Each facility shall maintain a copy of the order, complete with changes and supplements for reference purposes. When inserting changes to the order, enter the number, effective date, initials, and date entered on the inside cover of this order.