Water on the move · a world-scale map
Find any city, street or address; switch on the terrain and NASA's live water layers; and where we have a river gauge, read the flood grade — normal · medium · high · high+ — with the lead time it buys you. It is awareness, not a forecast, and it never says a place is safe.
Layer control top-right: Topography (OpenTopoMap), NASA true-colour, and live NASA water layers — rain (GPM/IMERG), snow & ice (MODIS), sea-surface temperature (GHRSST). A grade is shown only where a gauge covers the spot; its absence is never a promise of safety. Search © OpenStreetMap/Photon · terrain OpenTopoMap · elevation Open-Meteo · water & climate NASA EOSDIS GIBS / NASA POWER · grades LINUS Times floodwatch (USGS + NWS).
The grade above is the same one behind our flood-safe camping tool. If you are choosing a campsite by the water, search it here for its grade and lead time — the minutes between a scare and a phone call no parent should get — and, in any doubt, it points you upstream to the National Weather Service and to higher ground. It never overrides an official warning; it amplifies it.
Open the full camping tool → Search a campsite above ↑Why floods are getting harder to read
The slow rise · a warming climate
Warmer air holds more moisture, so rain falls harder; warmer seas stand higher, so coasts flood on smaller storms. Watch it on the map as the rain and sea-surface temperature layers.
For every 1 °C of warming the atmosphere holds ~7% more water vapour (Clausius–Clapeyron). More water aloft is more water that can fall.
The sudden release · ice & glaciers
High up, meltwater pools behind fragile dams of rock and ice; when one fails, a lake empties downstream in minutes — a glacial lake outburst flood — often on a clear day. See the snow & ice layer for where the cryosphere is.
The Hindu Kush–Himalaya (Nepal, Tibet, Bhutan, N. India, Pakistan) holds thousands of glacial lakes; the recent Nepal/Tibet outburst floods are part of this pattern, not apart from it.
Awareness, not a forecast. It does not, and will never, tell you a place is safe. Flood danger turns on local conditions in the hours around you, and only the official services measure those. In any doubt, act early and follow them — the water does not wait for certainty, and neither should you.
Behind both lenses is one uncomfortable truth about scale.
Read the letter — on what engineering cannot do →