What is StormSync VT/OI?
The fastest NWS alerts you can get without working for a TV station, explained end to end.
Built on NWWS-OI.
The NWS pushes alerts through several different channels. Most weather apps pull from the public REST API at api.weather.gov, which typically adds a 60 to 120 second delay between issuance and delivery, because the app has to ask whether anything new exists.
StormSync VT/OI connects directly to the NOAA Weather Wire Service Open Interface (NWWS-OI), an authenticated XMPP feed that broadcasters, emergency managers, and commercial alerting services rely on. Nothing polls. The wire pushes, and products arrive within about 100 milliseconds of issuance.
This is the same feed that fires off the Emergency Alert System on broadcast TV. StormSync makes it available as a free desktop application.
How it works.
While running, StormSync holds a persistent XMPP connection open to NWS servers. The wire operates as a single one-way room: a service account emits each product as a message stanza carrying the raw text, and every connected client receives it at the same instant. Every text product from any Weather Forecast Office or National Center is delivered straight to your machine as it is issued.
Each product is then parsed locally for VTEC codes, UGC zones, phenomena type, and severity. Tornado warnings get further broken down by sub-type (Emergency, PDS, Confirmed, Observed, or Radar Indicated) and assigned a severity rank from 1 to 115.
Everything is stored locally in a SQLite database. Nothing is sent from your machine.
What happens when the wire moves.
NWWS-OI is served behind two domain names, and NWS performs planned server transitions for patching and maintenance. During a transition, clients need to reconnect to pick the newly active server back up.
StormSync handles reconnection automatically rather than sitting silent on a dead socket. Connection state is surfaced in the app so you always know whether you are actually listening, and the Performance Log records how each build held up during real severe weather events, bugs included.
Who is it for?
StormSync is built for weather enthusiasts, storm spotters, hobbyist meteorologists, broadcasters, and anyone who wants NWS alerts with real speed and detail. It is free, requires no subscription, and with Central Feed requires no credentials either: just download and go.