National Weather Service Training Center

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Cooperative Observing Site

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inactivation ... reactivation

In addition to the installation or closing of a cooperative observing site, you may need to change of the status of an active site to "inactive" or "reactivate" an inactive site. The information provided below is designed to help you with this process.


An operational National Weather Service (NWS) cooperative weather station (CWS) may be placed in an "inactive status" when situations develop in which scheduled observations cannot be not taken for a short period of time but scheduled observations are expected to resume. A station may remain inactive for no more than six months before being "reactivated" to observation status.

Generally, a NWS Representative you must place a station in inactive status if:

The period of observation continuity is broken
which results in a scheduled chart or form
to be missing at the National Climatic Data Center.
These observations are expected to resume within six months.

Examples of situations which might initiate the inactivation process include:

  • Loss of an observer or disruption due to construction at the site.
  • An extended trip taken by the official cooperative weather observer (CWO) where no backup observer can be enlisted to maintain continuity in the station's scheduled observations is also an example of a situation which would require the NWS Representative to make the station inactive.
  • An inability to recruit a replacement Cooperative Observer for the station may also require inactivation; however, if the NWS Representative responsible for the station determines that it is unlikely that a suitable replacement observer can be recruited in the area, the station becomes a candidate for closure or automation.
  • If circumstances indicate that the station is unlikely to or cannot return to active status by the end of six months, the station should be "closed." For example, if a station is placed in inactive status and four months later you find that it cannot be reactivated for another six months, the station should be closed as the inactive period will extend well beyond the maximum inactivation period of six months. The station can be "closed" through submission of a B-44 immediately after learning that the station will not be reactivated. (Check our web page on closing a station.)

    If the closed station unexpectedly becomes ready to resume operation at some time in the future, it must be opened as a new station. As is done with any other newly established station, a B-43 must be submitted through region so that a station number can be issued by the National Climatic Data Center (NCDC). (Check our web page on installation of a station.) The B-43 should indicate if the new station is compatible with the closed station. If so, the NCDC could reauthorize the use of the station number used before closing. However, only the NCDC has the authority to make this determination. Should it be determined that these data from the new station are incompatible with the old data, it is likely that a totally new station number will be assigned.

    The decision to the close or automate an official cooperative weather station rests with the appropriate Regional Headquarters (RH). Only after a review of NWS requirements and a thorough evaluation of the criticality of the station's data to NWS operations will RH make a determination. The NWS Representative is authorized to make a station inactive but cannot close an official CWS. In fact, no local NWS official can authorize closure of an official Cooperative Weather Station without a Regionally approved B-43 (Request for Establishment or Change in Status of Cooperative Station). The responsible NWS office must submit a B-43 to RH requesting closure authorization. (Check the station closure web page for details). However, a B-43 is not required to inactivate a station since the station is expected to resume operation within six months.

    It is also the responsibility of the appropriate NWS office to prepare a B-44 (Cooperative Station Report) to document inactivations. This process should be completed in a timely manner in accordance with national, regional and/or local NWS policy. This B-44 documenting the inactivation of a station will inform the NCDC that there will be a temporary break in the records for the station. Once notified, the inactive station's monthly form will not be charged as missing. Until NCDC is notified by B-44 that a station is inactive, the NWS office will continue to be charged for a missing form/report from the CWS. Therefore, it is of utmost importance that B-44s are processed as soon as possible after an event which causes a break in the station's records receipt at NCDC.


    An operational NWS cooperative weather station may be returned to "active status" when observations resume. If the station was closed rather than placed in an inactive status, reactivation is not an option. The closed station was terminated when closed. A closed station cannot be reopened and can only be returned to an active status by opening it as a "new" station. Only an inactivated station may be reactivated.

    As NWS Representative you may return an inactive CWO to active status if:

    The station's period of observation continuity was broken
    as a result of the station being officially inactivated.
    The reactivation will provide data compatibility
    with data from the station prior to being inactivated.

    The NWS Representative responsible for reactivating the station is also responsible for preparing the B-44 to document the station's return to active status in a timely manner.

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    Last reviewed or updated on 8/04/00