Begin with the exact product name
The National Weather Service tornado-alert explanation distinguishes watches, warnings and tornado emergencies. A watch concerns conditions favourable to tornadoes; a warning concerns a detected or indicated threat. These are not merely different colours for one set of confirmed tornado reports. Read the full official message rather than translating a polygon directly into a claim about where a tornado touched down.
The Storm Prediction Center provides outlook and watch information. An outlook is not a list of individual tornadoes or an address-specific warning. Inspect the selected product, valid day and hazard before sharing it. A map for tomorrow should not be presented as a measurement of storms already occurring today.
Keep time and geography attached to alerts
The NWS locality and alert pages lead to the current messages relevant to a place. Read the issue time, valid period, affected area and subsequent updates. A saved warning image can remain online after its valid period. Its historical value does not make it current, and a new browser retrieval time does not renew the warning.
When comparing county-based overviews with detailed message geometry, note the display's scale and selection. A broad overview may simplify how information is shown. Do not infer that every location in a highlighted county experienced the same event, or that a point immediately outside a screenshot's shaded region has been independently assessed by that image.
Reported events are a separate layer
A report of a past event, a forecast outlook and a current warning serve different purposes. For a research comparison, match the location and time window before interpreting an apparent overlap. Keep preliminary reports identified as reports rather than converting them into a verified track or final impact assessment. Do not infer an official cancellation from the absence of a point on a different provider's map.
The PocketWorld disaster explorer supplies available global storm context, not a complete US tornado-warning or report network. A global storm marker cannot establish whether a local NWS message applies. The source directory and methodology explain provider coverage and retained information. Official emergency channels take priority, and this article should not be used as an operational decision tool during a warning.
For an explanatory note, retain the issuing organization, product type, issue time, valid period and original link. If comparing an SPC outlook with an NWS warning, label both clearly instead of treating them as interchangeable forecasts. This preserves what each source says without inventing a real-time national tornado map from incomplete global records.
Data sources
References are linked beside the explanations above. This evergreen guide does not report current incidents.