Methodology & Data Sources
Disclaimer: Informational only. This page explains data sources and methodology and does not provide forecasts, alerts, or emergency instructions.
Why This Page Exists
Steadfast Storm Shelters provides tornado-related informational tools to help users understand historical and recent storm activity using official public data sources.
Because tornado data can vary by source, update timing, and reporting methodology, this page explains where the data comes from, how it is processed, and what limitations apply.
Our goal is transparency — not prediction, risk scoring, or emergency guidance.
Primary Data Sources
All data displayed across Storm Mode, Tornado Tracker, and Tornado History tools is sourced from official U.S. government and meteorological agencies.
National Weather Service (NWS)
The National Weather Service provides official tornado warnings and severe weather alerts issued by local Weather Forecast Offices.
Used for:
- Tornado warnings
- Warning polygons
- Warning issuance history by location
Official source:
🔗 https://www.weather.gov
NOAA Storm Events Database (NCEI)
The NOAA Storm Events Database contains confirmed historical tornado records, including post-event surveys and finalized reports.
Used for:
- Confirmed tornado occurrences
- Long-term tornado history by location
- Historical event counts
Official source:
🔗 https://www.ncei.noaa.gov/access/search/data-search/storm-events
Storm Prediction Center (SPC)
The NOAA Storm Prediction Center provides Local Storm Reports (LSRs), which include preliminary tornado reports submitted by trained observers and meteorologists.
Used for:
- Recent tornado reports
- 24-hour tornado tracking
- Preliminary event listings prior to confirmation
Official source:
🔗 https://www.spc.noaa.gov
Storm Mode Methodology
Storm Mode displays active severe weather information using official National Weather Service data.
Includes:
- Active tornado warnings
- Active tornado watches
- Severe thunderstorm alerts
- Radar visualization from approved providers
Important notes:
- Storm Mode reflects current official alerts only
- It does not predict future tornado activity
- Users should always rely on official NWS alerts and local emergency management
24-Hour Tornado Tracker Methodology
The 24-Hour Tornado Tracker displays recent tornado reports using a hybrid reporting window to reflect how tornado data is actually published.
Inclusion criteria:
An event is shown if:
- The tornado occurred within the last 24 hours OR
- The report was officially published or updated within the last 24 hours
This approach accounts for:
- Delayed damage surveys
- Overnight or rural confirmations
- Post-event reporting timelines
Event status:
- Reports from SPC Local Storm Reports are labeled Preliminary
- EF ratings may not be available immediately
Tornado History Methodology
The Tornado History tool provides historical context by location, combining tornado warning data and confirmed tornado records.
Includes:
- Tornado warnings issued by the National Weather Service
- Confirmed tornado events from NOAA databases
- Location matching performed at the county level
Time ranges displayed:
- 10-year historical totals
- All-time records (based on data availability)
Important clarification:
- Tornado warnings cover broad geographic areas
- Not every warning results in a tornado touchdown
- Historical frequency does not imply future risk
Data Limitations
- Tornado data is subject to revision after surveys
- Reporting timelines vary by event and location
- EF ratings are assigned after post-event analysis
- Some rural events may be reported later than urban events
- Location matching is approximate and based on available data
This system is intended for educational and informational purposes only.
What These Tools Do Not Provide
- No tornado predictions
- No risk scoring
- No safety guarantees
- No emergency alerts
- No replacement for official warnings
Always rely on:
- National Weather Service alerts
- Local emergency management guidance
- NOAA Weather Radio.
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