Partial County Alerting for NOAA Weather Radio (NWR) and the Emergency Alert System (EAS), with new service enhancements, begins in 2024 for select US counties.
The National Weather Service (NWS) broadcasts weather warnings and Non-Weather Emergency Messages (NWEMs) via NWR. NWR also serves as a primary source of information for the nation’s EAS.
NWR and EAS are both generally viewed as county-based systems. However, this is particularly problematic for select counties because even if only a small portion of a county is included in a warning, the warning’s NWR and EAS dissemination translates to the entire county. This issue is most common for very large, uniquely-shaped (e.g., rectangular) or uniquely-configured (e.g., islands) counties.
Both NWR and EAS allow a county to be divided into several fixed areas (partitions). Each partition is associated with a unique, six digit location code. Eight WFOs have successfully assigned partial county codes to one or more of their counties (most recently by ). Details on what each of these WFOs are already doing are available through the link on the right side of this page. We refer to this more-targeted dissemination of warnings via NWR and EAS as Partial County Alerting (PCA). PCA implementation is not appropriate for every US county. The usefulness of PCA is generally reserved for very large or uniquely-shaped counties, such as elongated counties.
When PCA is implemented, NWR listeners with Specific Area Message Encoding (SAME)-equipped receivers carrying the Public Alert™ logo can easily select a unique, six digit location code for their local area and receive automated notifications of WFO-issued warnings only for the programmed partition(s). PCA reduces “listener fatigue” by reducing the receipt of warnings for distant parts of a county.
With PCA, broadcasters may choose to limit the activation of EAS to specific county areas.
NWS will enhance the information we provide to the existing PCA service level. Details on these improvements are provided at the bottom of this page. For example, based on WFO decisions with local officials and emergency managers, PCA may also be used for NWEMs with this new service level.
NWS will issue WFO-specific Service Change Notices. Announcements will be aired on NWR. Details will be provided on your WFO web page with county maps showing the partition boundaries, the SAME location codes to use with SAME-equipped NWR receivers and the complete list of warnings using PCA by the WFO.
The implementation of PCA is an opt-in service for those who wish to receive warnings more applicable to their local area. If NWR listeners using Public Alert™ receivers wish to continue receiving all warnings broadcast by a specific station for their county, they do not need to make any SAME location code changes - they will retain the SAME code beginning with zero. Note that some stations do not broadcast warnings for every part of a county. NWR users are encouraged to consult each transmitter-specific page which details the “Areas Receiving Alert Tones.”
The NWS's national expansion of PCA for select counties includes the following enhancements:
Note that PCA does not result in the direct dissemination of a forecaster-defined polygon (or a NWEM defined by a polygon) via NWR and EAS. However, the implementation of PCA will reduce our warning footprint on NWR and EAS from the entire county to one more closely representing the area defined by the polygon warning (or a NWEM defined by a polygon).
To receive the full benefits of this enhanced dissemination capability, consumers must use a SAME-equipped NWR receiver and program in the six digit code associated with a county partition. Details on programming receivers for partitioned counties are online at weather.gov/nwr/sameenz
The six digit location code for a county partition will be provided on the national NWR county pages.
The national NWR web pages (https://www.weather.gov/nwr) provide more information about SAME and a list of NWR receiver manufacturers.
WFO NWR webpages will also contain more detailed information on their use of PCA and the six digit location codes for partitioned counties.
Please submit any comments, suggestions or questions to:
Mr. Brian Miretzky
brian.miretzky at noaa.gov
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