Current version:

CAP‑Warn is a modern weather alert system designed as a full replacement for older Skywarn scripts like AutoSky. It uses the current National Weather Service (NWS) alert format and provides a far more reliable, automated experience for repeaters and AllStar nodes.

It is not Skywarn totally my own code. It is a replacement not written in python.

Because CAP‑Warn is distributed through an APT repository, your system automatically receives updates — no manual patching, editing, or file replacement required.

CAP‑Warn retrieves alerts directly from the National Weather Service CAP system and the National Hurricane Center (nhc.noaa.gov). These alerts are converted into high‑quality audio and played over your node, keeping operators informed even during rapidly changing weather conditions.

HISTORY
This is based on node manager I released in 2023 for GMRS Cap Warn was inside that as well as the CPU temp monitor
That was all based on MMWeather released in 2015. for COWP
This is a major improvement In that it no longer uses my custom installer its now using APT-GET.

2. Modern NWS API Compatibility

Although the NWS API returns alerts in GeoJSON/JSON‑LD, the underlying data is still CAP 1.2, the official federal standard for public warning messages. The API simply transforms the raw CAP XML into a clean, consistent JSON structure. This avoids the formatting issues, namespace problems, and broken XML that caused many older scripts to fail when legacy CAP endpoints were deprecated.

CAP‑Warn uses the modern, supported, and recommended NWS API format, ensuring long‑term compatibility with the current alerting system.

3. Automatic Location & Zone Detection

CAP‑Warn automatically determines your alert coverage using your device’s GPS position, then expands that location into the correct NWS forecast zone, county/parish zone, and fire weather zone.

This means the system always reports the alerts that actually apply to your area — without requiring you to manually enter UGC codes, county IDs, or zone numbers like older scripts did.

By combining point‑based alerts with zone‑level alerts, CAP‑Warn captures everything from hyper‑local polygon warnings to broader county‑wide advisories, ensuring complete and accurate weather alert coverage for your station.

Muting during nets by a chron script. This is a manual process you set timers

4. Text‑to‑Speech Options (VoiceRSS vs Piper)

CAP‑Warn supports two different text‑to‑speech engines:

VoiceRSS (Recommended) https://voicerss.org/

• Most natural, broadcast‑quality voice
• Very fast
• Requires internet
• Requires a free API key

Piper (Offline Neural TTS) asl-tts

• Works with no internet
• Included in the ASL3 repository asl-tts
• Slower and more CPU‑intensive on Raspberry Pi

If you leave the API key blank during installation, CAP‑Warn automatically switches asl-tts. Notice in testing on a pi 3b asl-tts overheated the cpu which will cause problems recommend VoiceRSS on a PI.

5. PI Hardware (Temperature, Voltage, Throttling)

CAP‑Warn includes a full Raspberry Pi hardware‑health monitoring system that checks for:

• High CPU temperature
• Low‑voltage conditions
• CPU throttling events

These alerts help identify:

• Weak or failing power supplies
• Overheating Pi boards
• Fan failures
• Heavy CPU load conditions

CAP‑Warn reads the Pi’s real‑time firmware flags to detect when the system is running too hot, when voltage drops below safe levels, or when the CPU has been throttled to protect the hardware.

PI hardware is autodetected fully Cloud server compatible

Installation Options

1. Automated Install (Recommended)

CAP‑Warn works on a wide range of systems. For example, it supports:

• ASL3
• Debian 12/13
• Raspberry Pi
• Cloud nodes
• Bare‑metal nodes

Just run:

curl -sSL [https://raw.githubusercontent.com/tmastersmart/cap-warn/main/install_capwarn.sh](https://raw.githubusercontent.com/tmastersmart/cap-warn/main/install_capwarn.sh) | bash

Once executed, this installer:

• installs the GPG key
• adds the repo
• installs dependencies
• installs CAP‑Warn
• places you in the correct directory
• tells you to run setup.sh

2. Manual Install (For those who prefer full control)

Step 1 — Install required PHP modules and tools

asterisk-core-sounds-en-gsm sounds may not be needed if you already have sounds.
We need numbers and sounds from the normal ast sounds.

sudo apt install php-cli php-curl php-xml php-mbstring php-json sox curl logrotate asterisk-core-sounds-en-gsm

core sounds may not be needed if you already have sounds.

Step 2 — Install the GPG key manually

curl -sSL [https://raw.githubusercontent.com/tmastersmart/cap-warn/main/debian/public.key](https://raw.githubusercontent.com/tmastersmart/cap-warn/main/debian/public.key) \
  | sudo gpg --dearmor -o /usr/share/keyrings/capwarn.gpg

Step 3 — Add the APT source manually

sudo nano /etc/apt/sources.list.d/capwarn.list

Add:

deb [arch=all signed-by=/usr/share/keyrings/capwarn.gpg] [https://raw.githubusercontent.com/tmastersmart/cap-warn/main/debian](https://raw.githubusercontent.com/tmastersmart/cap-warn/main/debian) stable main

After saving, continue with the next steps.

Step 4 — Update APT

sudo apt update

Step 5 — Install CAP‑Warn

sudo apt install cap-warn

Step 6 — Run setup

cd /usr/share/cap-warn
sudo bash setup.sh

At this point, installation is complete.

What About HamVoIP?

CAP‑Warn is now designed for Debian‑based systems. Originally, it was written for HamVoIP GMRS nodes, but much has changed since 2023. Today, the recommended platforms are:

• ASL3
• Debian 12/13
• Raspberry Pi OS

Final Thoughts

CAP‑Warn is built for hams who want:

• reliable weather alerts
• modern CAP parsing and hurricane support
• clean audio
• easy installation. You don’t have to know how to edit files.
• active maintenance. There will be updates.
• compatibility with ASL3 and Debian 12/13
• Works with apt-get and apt-get update cap-warn

Ultimately, CAP‑Warn provides a dependable, modern solution for weather alerts on AllStar systems.

CAP-Warn is a modern weather alert system for AllStar nodes that utilizes Common Alerting Protocol formats. It provides automated updates via APT-GET and retrieves weather data directly from the National Weather Service and National Hurricane Center. The software converts alerts into audio for broadcasting on repeaters and nodes.

The system supports Debian-based platforms, including ASL3 and Raspberry Pi OS, through automated or manual installation processes. While originally developed for HamVoIP, current versions prioritize newer operating systems for better maintenance and reliability. The software aims to offer a dependable replacement for legacy weather scripts.

Updates:

You will get updates through the update repo. Im still testing so there will be several updates until I am satisfied with the results. As time goes by I need to test this in actual storms not just with test data. If you see any strange errors or problems. or suggestions please write a comment.

Manual Upgrade Instructions (for existing CAP‑Warn installs)

To manually upgrade CAP‑Warn to the latest version, run the following commands: After running the first command you should see a message if the version has changed. Then run the second command it will not override your setup.

Code

sudo apt-get update
sudo apt-get install --only-upgrade cap-warn or just 

sudo apt-get update cap-warn

That’s it — this will pull the newest package from your repository and upgrade CAP‑Warn without touching your configuration or logs.

If you see it doing anything strange please report. I use it myself so I should notice bugs but sometimes you may be setup different than me and the weather service may use different alerts in your area.

There is a file located at /var/log/cap-warn/words_to_add.log which will show the auto upgrade for any new alerts NWS.
Sending me this log will help so those sound files can be added to the release.

Cyclone Alerts. Tested in the past but this is new reformatted code, so it needs to be tested with a active storm. It should read the alerts as they come in and not repeat them. Expecting this will need to be adjusted.

UPDATES:

1. GPS support for the $17 gps units so your mobile node will report the local alerts not those back at your home. Great for travelers and truck drivers. Should be easy setup just plug in.
2. Pushover support. Pushover would work great at remote sites instead of over the air messages temp and low voltage messages they could be sent to your phone.
3. APRS I have working code for this just not sure how im going to configure yet. Im leaning toward privacy mode so you have to be a set distance from your home location before it starts posting. And it will post with a error factor so its not exact. Much later after GPS is all tested and working. APRS would post into the net server not over the air so it will work everywhere. optional. (This is going to be a separate install for all-star,Pi-Star & WPSD nodes look for it soon.)
4. Create a special desktop version for non hams to mimic a weather radio.(later still working on this code)
   
   

The post CAP‑Warn: Modern Weather Alert Software for AllStar & ASL3 — A Reliable Storm Replacement System first appeared on Louisiana Nationwide.