The Amateur Radio Collective of Western Carolina (ARCWC) has launched a regional APRS bulletin service to provide weather notifications, system information, event notices, and other useful announcements to APRS operators across western North Carolina.

The project expands on one of APRS’s core capabilities: distributing timely information directly to amateur radio operators. While APRS is often associated with position reporting and vehicle tracking, it was designed as a real-time information and communications system capable of carrying messages, bulletins, announcements, weather information, alerts, and other local information.

What Are APRS Bulletins?

APRS bulletins are short text messages intended for multiple stations rather than a message addressed to one specific operator.

The APRS protocol defines bulletin addresses beginning with BLN. Numbered bulletin identifiers, such as BLN0 through BLN9, can be used for general bulletins, while APRS also supports group bulletins by adding a group name to the address. Bulletin text is limited to 67 characters, so messages are intentionally short and designed to communicate the most important information quickly.

Unlike normal station-to-station APRS messages, bulletins are not intended to require individual acknowledgments from every station receiving them. They can be transmitted periodically so stations entering the area or coming online have an opportunity to receive the current information.

For ARCWC, the group identifier is ARCWC.

A bulletin addressed as: BLN0ARCWC is an APRS group bulletin intended for stations monitoring the ARCWC group.

How ARCWC Uses APRS Bulletins

The ARCWC bulletin system separates automated weather information from manually generated community announcements.

BLN0ARCWC through BLN9ARCWC are reserved for automated hazard bulletins. These slots can carry information including Tornado Warnings, Severe Thunderstorm Warnings, Flash Flood Warnings, watches, warning updates, cancellations, and significant Special Weather Statements.

For example: BLN0ARCWC: SVR Polk/Rutherford: 60mph wind, 1in hail x1815L

The short format allows important information to fit within the APRS 67-character limit while still identifying the type of hazard, affected area, important details, and relevant time.

Lettered bulletin slots are used for manually generated information. ARCWC currently supports categories including administrative notices, nets and meetings, repeater or system status, events and training, road information, facilities, and public safety information.

This allows APRS to serve as another information-distribution tool for the amateur radio community rather than simply showing where stations are located.

Weather Notifications

One of the primary purposes of the project is automated weather notification.

Recent severe weather across western North Carolina has provided an opportunity to test and refine the system under real-world conditions. When qualifying weather information is received, the system generates a condensed APRS bulletin and assigns it to one of the numbered bulletin slots.

The goal is not to replace official weather information or other alerting systems. Instead, the APRS bulletins provide another way for amateur radio operators who are already monitoring APRS to receive concise information about significant weather affecting the region.

Receiving ARCWC Bulletins

Operators using APRS-capable radios, software, or terminals may receive the bulletins directly through the APRS network. Availability over RF will depend on station location, local APRS coverage, propagation, and equipment configuration.

ARCWC also maintains a web page that mirrors the bulletins and documents the formatting used by the system: ARCWC APRS Bulletins

The page includes recent bulletins, bulletin identifiers, weather codes, manual bulletin categories, county abbreviations, and examples of how messages appear over APRS.

The ARCWC web page provides an easy way to view the information being distributed by the system, while APRS.fi provides another way to see the bulletins currently present on the APRS network.

More Than Position Tracking The bulletin project is also an opportunity to highlight what APRS can do beyond position reporting.

The ARCWC bulletin service puts that capability to work locally by creating a common method for distributing short, relevant information to APRS users throughout western North Carolina.

ARCWC currently has seven western North Carolina counties configured in the system: Buncombe, Haywood, Henderson, McDowell, Polk, Rutherford, and Transylvania.

As the project continues to develop, additional areas may be added based on APRS activity and interest. Operators who regularly use APRS in surrounding counties are encouraged to contact ARCWC if they would like their county considered for inclusion.

Feedback from APRS users is welcome as we continue testing and improving the system.