Storm Arwen25 Nov – 27 Nov 20212021-22 seasonScotland, England, Northern Ireland, WalesCat 4 · SevereFull storm page →
110 mph max gust36 flood warnings & alerts England28 warning areas12 rivers3 UK deaths
Worst-hit areas (warnings)
North Sea at Sandsend2
North Sea at Scarborough - North Bay2
North Sea at Scarborough - Sandside2
North Sea coast at Bridlington2
North Sea coast at Skipsea, Hornsea and Mappleton2
Worst-hit districts (warnings)
North Yorkshire20
East Riding of Yorkshire10
Redcar and Cleveland5
Norfolk3
Hartlepool2
Worst-hit rivers (warnings)
North Sea24
River Seven2
Avon, Swift, Claycoton1
Bure, Ant, Thurne1
Humber Estuary, Winestead Drain1
🌀 the whole storm
Rivers<50%50–7575–9090–100recordRainlight ⟶ torrential▲ risingwarningsevere🏠 you
⏩ Worst moment, aftermath, similar storms, the storm's fingerprint
🔎 checking what live river conditions resemble…
🏠 Your postcode in this storm: nearest gauges, the local fingerprint, similar moments
Type your postcode in the box above the map.
🌊 Every river in this replay, and add one
⚠️ Official warnings day by day, the severe ones, and the records broken
🔴 Records broken — rivers passing their highest level ever measured, as the clock reaches each moment
🗺 Map layers, the weather model, and how to read this replay
— isobarsLH
🌦 weather: waiting for a replay…
Overflow timing usually matches river rises because both are driven by the same rainfall — a timing match is not evidence that either caused the other.
The map shows the weather that caused the flood under the rivers it flooded, on one clock. Each circle is a river gauge: it grows and turns red as that river climbs toward the highest level ever measured there. ▲ beside it is how fast it is rising, in cm per hour. Each rain gauge glows with the rain of the last hour, on the same colour scale as the model's rain band under the map. The band and the isobars are ERA5, a reanalysis: a model run with the observations of the time, not measurements.
The small map in the corner is the whole weather system, so you can see where the low is while the main map stays on your area. Click it to zoom out, click again to come back.
The timeline under the map is your doorstep: rain every 15 minutes at the nearest rain gauge, the nearest river as a share of its record, warnings as flags. The future is ghosted until the clock reaches it, so at every moment you see only what a person there could have known. Click or drag on it to move the clock.
The panel on the right is right now, at your door: the last hour's rain, the river's level and rise, the warnings out, the pressure. Below it, the story: the moments that mattered, ticked off as the clock passes them. Click one to jump to it.
Speed is replay time per real second. At 1 hour per second a day takes 24 seconds. ← → step 15 minutes (with shift, an hour); space plays and pauses.
Enter your postcode in the box above the map and the map, the timeline and the story centre on your address, pulling in the river and rain gauges nearest to you. Warnings are England only (Environment Agency data).
FloodRadar
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