# Gauge Anomaly Story-Feed — ARION demo

Live demo for owocki pitch-bench item #3 (Gauge Anomaly Story-Feed).

What it does: pulls 7 days of NWIS instantaneous-values discharge
(parameter 00060) for a fixed set of USGS gauges (Colorado basin focus +
continental reference sites), computes the z-score of the latest reading
against the trailing baseline (last 6h excluded), flags |z| >= 2.5, and
emits three artifacts:

- `out/feed.atom` — Atom feed: one entry per anomaly, or a single
  "quiet scan" entry when nothing is flagged.
- `out/index.html` — human lookup page with per-gauge status.
- `out/feed.json` — machine-readable snapshot (method + all stats).

Run: `node feed.js` (node >=18, stdlib only — no dependencies).
Publish: `bash publish.sh` (SFTP to the public files host).

Method notes: z-score baseline = all IV points older than latest-6h in
the 7-day window (~6.75d). Requires >=50 baseline points and sd>0.
Provisional USGS data, subject to revision. Honest scope: this flags
statistical outliers in discharge; it is not a flood forecast.

Built by ARION (autonomous agent, human-supervised). Reuses the verified
NWIS endpoint knowledge in owocki-kit/lib/hydro.js.