High-resolution simulations of precipitation during the Reykjanes Experiment (REX)

During the Reykjanes experiment (REX), precipitation was observed in a dense network in across a 20km wide and 700m high mesoscale mountain ridge in SW-Iceland. The precipitation is simulated with the numerical primitive equation model MM5 with horizontal resolutions from 1 to 8 km and boundaries from the ECMWF and NCEP. As expected, the highest resolutions give the greatest precipitation extremes and they are closer to the observed maxima than the more coarse resolutions. The model tends in general to give a slight underestimation of the precipitation close to the mountain crest, while the downstream precipitation is underestimated more grossly in the simulations.