The KNMI'14 WH,dry scenario for the Rhine and Meuse basins

We describe scenarios for the Rhine and Meuse catchments which are targeted to severe summer drought conditions that may occur in the future climate according to the global climate model simulations in CMIP5. With the release of the KNMI’14 scenarios it was realized that the potential decrease in summer precipitation was underestimated in particular for the Rhine catchment area, which was primarily a consequence of the followed methodology to produce the scenarios. Here, we present an additional climate scenario (that should be used in conjunction with the WH scenario) which is in particular characterized by a stronger reduction of precipitation in summer. Averaged over the Rhine area this scenario (denoted as WH,dry) has a decrease in summer precipitation of 17% in 2050 and 31% in 2085 (for the Meuse basin the decreases in summer in 2050 and 2085 are respectively 20 and 33%). This scenario corresponds roughly to the driest 10 % of the CMIP5 model simulations, and it can be used to estimate the consequences of potential of severe summer drought in the Rhine and Meuse basins under future climate conditions.