The National Weather Service distributes alerts through several channels. Most weather apps and websites use the public REST API at api.weather.gov — which typically delivers products 60 to 120 seconds after they are issued.
StormSync VT/OI connects directly to the NOAA Weather Wire Service Open Interface (NWWS-OI) — an authenticated XMPP feed used by television and radio broadcasters, emergency management agencies, and commercial alerting services. Products arrive within seconds of issuance, before most other systems have received them.
This is the same feed that triggers the Emergency Alert System on broadcast television. StormSync makes it accessible as a free, open desktop application.
When connected, the application maintains a persistent XMPP connection to NWS servers. Every text product issued by any NWS Weather Forecast Office or National Center is delivered to your machine in real time.
Each product is parsed for VTEC codes, UGC zones, phenomena type, and severity. Tornado products are further classified by sub-type — Emergency, PDS, Confirmed, Observed, or Radar Indicated — and assigned a severity rank from 1 to 115.
All products are stored locally in a SQLite database. Nothing is transmitted from your machine.
StormSync is built for weather enthusiasts, storm spotters, amateur meteorologists, and anyone who wants to monitor NWS alerts with professional-grade speed and detail. Free, no subscription, open to anyone with NWWS-OI credentials.