HBV is normally started with t0 = 05:00 UTC. Until t0 HBV is updated with measured meteorological and hydrological data, the forecasting period is covered with COCH7COR.
COCH7COR initial time is 00 UTC (day-1), so the forecasting period covers normally 67h. Forecasts are checked hourly against defined thresholds, alerts are issued if 33% of the members exceed one of these thresholds.
COCH7COR is based on COSMOCH7. In COCH7COR the precipitation is scaled for several regions within Switzerland by the MeteoSwiss forecaster in duty. Example: for the eastern plains, COSMOCH7 shows 25 mm precipitation in 24h, the met forcaster assumes that 15 mm is realistic,then temporal and spatial distribution are kept from COSMOCH7, while the 24h-amount is scaled by 0.6. COCH7COR is available at about 08 UTC. if the hydrological forecast is started earlier, then yesterdays run is used with a remaining lead time of 43 h. if today's run is available the lead time is 67 h.
Forecasts and alerts are provided for the following stations: Aare-Brugg, Aare-Murgenthal, Emme-Emmenmatt, Kleine Emme-Littau, Limmat-Baden, Reuss-Mellingen, Rhein-Basel, Rhein-Diepoldsau, Rhein-Rekingen, Rhein-Rheinfelden, Thur-Andelfingen, Thur-Halden