County Coverage

Partial County Description 

Users with NWR receivers equipped with Specific Area Message Encoding can program their radios with a 6-digit county code to receive alerts for one or more counties. The NWS also sends warnings to the Emergency Alert System (EAS). Broadcasters use EAS to interrupt programming for vital NWS warnings.

Because NWR is county based, if an NWS office forecasts that even a small part of a county is impacted by a storm, the entire county is alerted. Both NWR and EAS allow NWS to divide a county into 2-9 partitions, each having a unique 6-digit code. More than 10 years ago, four NWS offices (Duluth, MN; Glasgow, MT, Rapid City, SD,  and Tucson, AZ) successfully implemented partial county codes. Most SAME-equipped NWR receivers can read these codes. By using the SAME partial county location codes, these WFOs have successfully issued warnings for predefined parts of a county, substantially reducing the “False Alarm Area” and “listener fatigue.”

Resources to learn more about partial county alerting are listed below:

• Partial County Alerting (PCA) Overview

• PCA Technical Discussion

• PCA Benefits for Residents and Broadcasters

• PCA Example: Flash Flood Warning

• NWS Offices Using PCA