U.S. DEPARTMENT OF COMMERCE
                                                               National Oceanic and Atmospheric Administration
                                                               NATIONAL WEATHER SERVICE
                                                               Silver Spring, Md. 20910
                                                                                                                                    W521x1
                                                                October 12, 1982

TO                 : All Holders of Operations Manual

SUBJECT     : Transmittal Memorandum for Operations Manual Issuance 82-16

1. Material Transmitted:

WSOM Chapter B-12, Standards and Procedures for Basic Weather and Synoptic Observation Programs at NWS Stations.

2. Summary:

This chapter provides an updated description of the standards and procedures for basic weather and synoptic observations at stations staffed by NWS or contract personnel. The significant changes to this chapter include:

3. Effect on Other Instructions:

Cancels WSOM Chapter B-12, issuance 74-14, dated July 8, 1974.

 

Richard E. Hallgren
Director, National Weather Service

Issue Date Org. Code         NATIONAL WEATHER SERVICE      Part     Chap.
10-12-82     W521x1                  Operations Manual                                B          12

Table of Contents:

1. General

1.1 Purpose
1.2 Organization of Chapter
1.3 Definition of Terms "Program" or "Observation Program"

2. Establishing Observation Programs at NWS-Staffed Stations

2.1 Criteria for Establishing NWS-Staffed Observation Programs
2.2 Criteria for Establishing New NWS Observation
2.3 Selection of Observation Site at NWS Stations
        2.3.1 Minimum Acceptable Site for Basic Weather and Synoptic Observations
2.4 Instrumentation of NWS Observation Stations
        2.4.1 Equipment at Basic Weather Observing Stations
        2.4.2 Equipment at Synoptic Observation Stations

3. Discontinuing Observation Programs Due to Station Closures

3.1 Observations
3.2 Equipment and Maintenance

4. Operation of Observation Programs

4.1 Observing Instructions Used
4.2 Recording Forms Used for Surface Observations at NWS Stations
        4.2.1 Historical File of Surface Observation Forms
4.3 Technical Library
4.4 Quality Control of Instruments
4.5 Changing NWS Observation Programs
        4.5.1 Authority for Making Changes to NWS Observation Programs
        4.5.2 Authority for Making Temporary Changes in NWS Observation Programs
        4.5.3 Continuation of Climatological Data Under Reduction of Hours of Operation
4.6 Acknowledgment of Weather Messages

5. Use of NWS Observation Stations as Supervisory Offices

 

1. General.

1.1 Purpose. This chapter provides standards and procedures for establishing and operating basic weather and synoptic observation programs at National Weather Service (NWS) offices. It also outlines NWS policy on observation programs when stations are closed.

1.2 Organization of Chapter.

Section 2 -- Gives criteria for establishing observation programs at NWS-staffed stations.

Section 3 -- Describes NWS policy on discontinuing observation programs due to station, closures.

Section 4 -- Describes the operation of observation programs.

Section 5 -- Describes the use of NWS observation stations as supervisory offices.

1.3 Definition of Terms "Program" or "Observation Program." As used in this chapter, these terms refer to all station activities, equipment, schedules, and procedures related to making, recording, or disseminating the observations for which the station is responsible.

2. Establishing Observation Programs at NWS-Staffed Stations.

2.1 Criteria for Establishing NWS-Staffed Observation Programs. Assuming funds and personnel are available, observation programs may be established at any existing NWS office.

2.2 Criteria for Establishing New NWS Observation Sites. New sites may be established if:

2.3 Selection of Observation Site at NWS Stations. The selection of the observation site should be a coordinated effort by the Regional Data Acquisition and Facilities Divisions. The primary considerations when selecting the site are:

With regard to item b., a site is considered available if, in combination with all other observation sites at the station, it allows the observer to complete an observation in 15 minutes.

2.3.1 Minimum Acceptable Site for Basic Weather and Synoptic Observations. No NWS station should be established to make basic weather or synoptic observations unless the site provides an unobstructed view of: (1) at least half of each quadrant of the natural horizon with no more than 45 degrees continuous obstruction; (2) at least 80 percent of the celestial dome (as defined in Federal Meteorological Handbook (FMH) No. 1); and (3) the direction from which weather most often approaches the station. If the station is at an airport, the elevation of the site should be within 100 feet of the field elevation and have an essentially unobstructed view of the primary instrument runway(s). The location should also provide sites for determining cloud heights, temperature, dew point, pressure, and wind speed and direction that meet the criteria in WSOM Chapter B-11.

2.4 Instrumentation of NWS Observation Stations. All NWS stations should have the following instruments.

2.4.1 Equipment at Basic Weather Observing Stations. NWS stations taking basic weather observations should have:

Other equipment may be added to the station as necessary to satisfy additional data requirements.

2.4.2 Equipment at Synoptic Observation Stations. NWS stations taking synoptic observations should have:

a. a psychrometer and extreme thermometers exposed in an instrument shelter,

b. a mercury barometer and barograph,

c. a ceiling light (for nighttime observations),

d. balloons and inflation equipment (for daytime observations),

e. a wind direction and speed system, and

f. a precipitation gage.

Other equipment may be added to the station as necessary to satisfy additional data requirements.

3. Discontinuing Observation Programs Due to Station Closures. When a decision is made to close a station, the following outlines NWS policy regarding observations, equipment, and maintenance.

3.1 Observations.

3.2 Equipment and Maintenance.

4. Operation of Observation Programs.

4.1 Observing Instructions Used. Basic weather observations will be made in accordance with the instructions in FMH No. 1. Synoptic observations will be made in accordance with FMH No. 2.

4.2 Recording Forms Used for Surface Observations at NWS Stations. The following forms will be used by NWS stations making basic weather and/or synoptic observations:

NWS stations taking incomplete observations, primarily for climatological observations (e.g., NWS city offices), will use WS Form B-16. Climatological data will be summarized daily on WS Form F-6 at all NWS stations that use MF1-10A and B or WS Form B-16.

4.2.1 Historical File of Surface Observation Forms. Retain corrected carbon copies of the surface observation forms on station for 5 years. After 5 years the copies may be offered to a local public library, public institution, or university, etc., capable of archiving the data for public use. If no local user can be found, the forms may be destroyed after the 5-year retention requirement has been satisfied.

4.3 Technical Library. The official in charge at NWS stations is responsible for assembling a technical library and for keeping it up to date. WSOM Chapter A-15 explains the procedure for getting publications for the station library. That chapter also gives a list of publications recommended for the library. In addition to the publications listed in WSOM Chapter A-15, all NWS observing stations should have the following:

Federal Meteorological Handbooks:
        FMH No. 1, Surface Observations (Parts A and B)
        FMH No. 2, Synoptic Code
        FMH No. 9, Aviation Weather Observations for SAWRS and LAWRS

Weather Service Observing Handbook:
        WSOH No. 2, Substation Observations

Training Papers:

Training Paper No. 5, Training Guide in Aviation Weather Observations for SAWRS and LAWRS
Training Paper No. 9, Training Guide in Surface Aviation Observations
Training Paper No. 12, Training Guide in Surface Synoptic Observations

International Cloud Atlas (Abridged Atlas)

These publications (with the exception of the cloud atlas) are available from the NLSC.

4.4 Quality Control of Instruments. In addition to the instrument checks made by personnel from the RH at the time of their visits, FMH No. 1 and parts of Engineering Division Maintenance Notes contain instructions dealing with preventive and corrective maintenance and instrumental comparisons. Some of these comparisons and maintenance should be done by station personnel. Each station supervisor should develop a comprehensive maintenance and comparison program suitable to the station needs. Between routine instrument checks, station personnel should note malfunctions and take the necessary action to see that repairs are made.

4.5 Changing NWS Observation Programs. Any changes in a station observation program schedules, elements, instruments, etc.) which affect the transmitted or recorded observation must be coordinated or approved (see paragraph 4.5.1) as required by NWS Headquarters (WSH). No changes will be made by a station without first coordinating the change with the RH. It is imperative that all permanent changes be documented in accordance with WSOM Chapter A-11.

4.5.1 Authority for Making Changes to NWS Observation Programs. WSH has the authority to establish or change observation programs (schedules, procedures, codes, standards, etc.) on a national level. The RH have the authority to establish or change observation programs within their region to the extent that such actions do not alter or conflict with national policy. For example, RH may require a station to report an element not required in other regions, but may not (without the approval of the WSH) make changes in reporting an element that would depart from an established standardized national procedure. Supervisors at NWS offices may make changes to programs locally only insofar as they do not affect the program as established by either WSH or RH.

4.5.2 Authority for Making Temporary Changes in NWS Observation Programs. Under emergency conditions (see WSOM Chapter A-12), the supervisor of the NWS station may change the observation program. However, such changes must not be for more than 24 hours unless authorization is received from the RH. In any event, the RH must be advised of the action as soon as possible. The RH may authorize temporary changes in station observation programs. If such changes affect transmitted data, the WSH (W1) must be advised of the change as soon as possible. This notification can be by telephone but must be confirmed in writing.

4.5.3 Continuation of Climatological Data Under Reduction of Hours of Operation. Unless a change in the observation program or reduction in hours of operation is because of an emergency, the WSH (W1) should be contacted to determine if the station climatological program should be continued or changed. If it is determined that the program should be continued, WSH will arrange for any additional equipment required (such as recording gages).

4.6 Acknowledgment of Weather Messages. Agreements for written acknowledgment of weather information transmitted between the NWS observing station and the control tower cab or traffic control facility may be made at the regional level or local level (subject to concurrence at regional level) provided:

5. Use of NWS Observation Stations as Supervisory Offices. An important part of the basic weather and synoptic observation programs is the quality control procedure used to monitor the data produced by these programs. Regional headquarters will assign NWS stations the task of supervising the observation program at other stations. An overview of NWS quality control policy is given in WSOM Chapter B-60. Details on station monitoring are given in WSOM Chapter B-62.