Improved error modelling for streamflow forecasting at hourly time steps by splitting hydrographs into rising and falling limbs

As expected, ERRIS-h is highly effective when applied to the zeroth lead time, dramatically reducing errors in the original GR4H simulations and reliably describing forecast uncertainty. We also show that ERRIS-h ensemble forecasts have smaller errors than deterministic simulations at all lead times and are reliable in ensemble spread even at 48 h lead times.