Active weather alerts displayed on the dashboard are sourced from the National Weather Service (NWS) public API:
NWS data is provided by NOAA/NWS and may be subject to change, delay, or outage. Alert polygons that are not included directly in the API response are retrieved from NWS zone geometry endpoints under the same domain.
The optional WWA map overlay image is sourced from NWS forecast pages:
Certain pages (including the Severe Weather Command Center) retrieve NWS text products such as fire weather outlooks, winter weather outlooks, and excessive rainfall discussions via:
Convective outlooks (Day 1–3), fire weather outlooks, Mesoscale Discussions, and related severe weather products are sourced from the NOAA Storm Prediction Center:
This includes GeoJSON outlook boundaries and discussion text displayed in the Severe Weather Command Center and on the main dashboard map overlay.
Local Storm Reports (LSRs) plotted on the map are retrieved from the Iowa State University IEM GeoJSON feed, covering the last 24 hours from all NWS offices:
Reports include tornado, wind, hail, funnel cloud, waterspout, and flash flood events. Source attribution (trained spotter, emergency manager, law enforcement, etc.) is included with each report.
The Alert History page (/history) retrieves historical storm-based warnings going back to approximately 2002 from the IEM VTEC archive:
Parameters include date range, NWS phenomena/significance code (e.g. TO.W for Tornado Warning), and WFO. Results include issuance time, expiration time, affected locations, and event identifiers.
Emergency event tagging on the History page uses the IEM emergencies database:
This endpoint returns all Tornado Emergencies and Flash Flood Emergencies on record since 1999, identified by WFO, year, event ID, phenomena, and significance. Results are cached server-side for one hour.
Active fire detections displayed on the map are sourced from the NASA Fire Information for Resource Management System (FIRMS) using VIIRS SNPP Near Real-Time data:
Fire data is fetched server-side via the FIRMS Map API. Only Nominal and High confidence detections from the past 24 hours are displayed. Fire Radiative Power (FRP) is used to determine marker size and color.
Tropical weather data and advisories are sourced from the NOAA National Hurricane Center:
Excessive rainfall outlooks (ERO), quantitative precipitation forecasts (QPF), winter weather outlooks, and surface analysis products are sourced from the NOAA Weather Prediction Center:
The NEXRAD radar tile overlay used on the map is provided by Iowa State University IEM / Mesonet. Mesoscale Discussion polygons are also sourced from IEM:
The default light base map tiles are provided by OpenStreetMap contributors via the standard tile CDN:
The dark base map tiles are provided by CartoDB / CARTO:
County-level population, household, mobile home, and age group data shown in the Impacts tab is sourced from the U.S. Census Bureau:
Census data is provided free of charge by the U.S. Census Bureau and is used in accordance with their public data terms. This data is pre-processed and stored as a static file — it does not update automatically.
County-level infrastructure counts (hospitals, schools, pharmacies, airports, power plants, etc.) are derived from the 2021 Census County Business Patterns (CBP) dataset:
CBP covers private and non-profit establishments only; government-operated facilities (e.g. public fire stations, police departments) are not included. Data is pre-processed and stored as a static file.
Dam counts per county are sourced from the USACE National Inventory of Dams (NID):
Data is pre-processed and stored as a static file. Dam counts include all dam types and hazard classifications.
Historical FEMA flood disaster declaration counts per county are sourced from the FEMA OpenFEMA API:
This data covers all federally declared flood disasters since 1953. It is used to indicate historical flood risk for affected counties in the Impacts tab. Data is pre-processed and stored as a static file.
This site is independently operated and is not affiliated with NOAA, the National Weather Service, the Storm Prediction Center, the National Hurricane Center, the Weather Prediction Center, or the U.S. Government. All trademarks and names belong to their respective owners.
Weather data is intended for general informational purposes only. Always follow official guidance from your local NWS office during severe weather events.