Weather, flooding and fire: observations versus guidance
Which layers are measurements, which are official warnings, which are model guidance — and where each reaches.
What you get: You can tell, for any weather layer, whether it shows something measured, something an agency issued, or something a model projects, and where it applies.
Steps
- Open Desks → "Weather desk" for satellite, radar, precipitation totals, warnings, the tropics, severe weather and day/night; or Desks → "Global hazards desk" for GDACS, earthquakes, volcanoes, fire and flood.
- Read each layer's row in the "LAYERS" panel before relying on it: it names the source and, where it matters, the region it covers.
- Click a warning or a detection to read its issuer and time.
| Kind | Examples | Reaches |
|---|---|---|
| Observed | Geostationary satellite; weather radar; wildfire thermal detections; river gauges (observed stage) | Satellite: the whole planet. Radar: national radar networks where RainViewer or NEXRAD has them — not everywhere. Gauges: United States |
| Reported (issued) | NWS alerts; wildfire incidents and perimeters; drought classes; GDACS disaster alerts | NWS, NIFC wildfire and the Drought Monitor: United States. GDACS: worldwide |
| Modelled (guidance) | SPC severe outlooks and ProbSevere; hail guidance; flood outlook; global fire weather | SPC, hail and flood outlook: United States. Fire weather (Copernicus GWIS): worldwide |
Guidance says what may happen; it is not a report that it has. Hail guidance, for example, is next-hour probability, not a verified hailstone.
What success looks like
You can name the issuer and the coverage of every layer you are reading.
Limits to know
- Most detailed weather warnings on the map are from United States agencies. Outside the United States, rely on GDACS, global fire weather, satellite and your national weather service.
- Radar shows precipitation where a national network is shared; a gap in the radar is a gap in coverage, not a dry sky.
Related
- What observed, aging, estimated, modelled and scenario mean
- Why a map can look empty
- Coverage, sources and freshness
- Understand time: live, recent past, ahead, history and scenarios
Last checked against the product on 23 September 2026. Live contents change; this describes how the product works.