The Ark Flood Monitor

Rainfall and river-level data are Environment Agency telemetry measurements collected server-side. The Collingham Core 6 forecast is generated server-side from four River Wharfe level stations (Netherside Hall, Addingham, Otley and Collingham) and two rainfall gauges (Littondale and Grimwith). All six required inputs must be healthy or the forecast is marked unavailable. The central and cautious forecasts extend to 12 hours; the central line is shown dashed after +10 hours to indicate lower confidence. Operational alerts come from the backend latched alert state and are not recalculated in the browser. This remains decision support rather than a guaranteed warning service.