redflag-check

Red Flag Warning zone check, address-in, plain-English-out.

A free, no-signup web tool + public REST API. Built in 48 hours during the 6/10–11 2026 Alameda County Red Flag Warning by a Fremont high schooler.

• Web UI: https://redflag-check.info
• Public API: https://redflag-check.info/api/v1
• API docs: https://redflag-check.info/docs
• OpenAPI 3.1 spec: https://redflag-check.info/openapi.yaml
• Embed widget: /embed/zone-check

Why this exists

The 6/9/2026 AC Alert text was sent county-wide. The actual NWS Red Flag Warning only covers NWS zone CAZ515 (East Bay Hills). Half the county was told to prepare a go-bag they don't need; some people in the hills don't realize the warning is right next to them and should pre-position.

This tool closes that gap. Type your address → get a clear yes/no, your evacuation zone, tonight's wind forecast, and a plain-English action checklist.

What's in this repo

• public/index.html, three-tab web UI: zone check, schools, buddy
• public/docs.html, public API documentation
• public/embed-zone-check.html, iframe-able widget for any external site
• api/v1/zone-check.ts, primary endpoint, address or coords → verdict + checklist
• api/v1/status.ts, current active Red Flag Warnings in any state
• api/v1/schools.ts, schools by radius or name search across California, plus the curated list
• api/v1/school-status.ts, per-school decision view (CIF AQI + wind + RFW)
• api/v1/buddy-template.ts, sms / mailto / .ics for buddy-check messages
• api/v1/health.ts, service + upstream health probe
• api/_lib.ts, Census geocoder, NWS fetchers, action checklist builder
• api/_schools.ts, curated (human-verified, East Bay) school list plus the bulk California CDE dataset, all with pre-resolved coordinates

Data sources

• NWS api.weather.gov, Red Flag Warnings + hourly forecast (public domain)
• US Census geocoding.geo.census.gov, address → lat/lng (public domain)
• Genasys Protect, official Alameda County evacuation zones (deeplinks)
• AirNow, air-quality reference

Integrators

This API is designed to be integrated by:

• County PIO / OES dashboards, surface address-level RFW status to constituents
• School district websites, show parents and principals the campus-level status
• News widgets, embed live RFW context in coverage
• Mutual-aid apps, generate buddy-check messages programmatically
• Insurance / utilities, internal dashboards that need normalized RFW data

No API key needed. Open CORS. 60-second edge caching. See /docs for endpoint reference.

License

MIT for the wrapper, UX, and aggregation logic. API responses contain public-domain data from NWS and US Census.

Disclaimer

Informational only. NOT an official emergency service. For official alerts, sign up at AC Alert. In case of fire, call 911.

The authoritative version is the Terms of Use & Disclaimer (source: public/terms.html). This project is maintained by a volunteer and is not affiliated with the National Weather Service, CAL FIRE, or any government or emergency-response agency. Note: the Terms are a good-faith, plain-English draft and have not been reviewed by an attorney.

Contact

Vedant Thakker · vedant28t [at] gmail [dot] com