Characterising patterns of heavy precipitation events in the eastern Mediterranean using a weather radar and convection-permitting WRF simulations

Abstract

Abstract. Heavy precipitation events (HPEs) can lead to natural hazards (floods, debris flows) and contribute to water resources. Rainfall patterns govern HPEs effects. Thus, a correct characterisation and prediction of rainfall patterns is crucial for coping with HPEs. Information from rain gauges is generally limited due to the sparseness of the networks, especially in presence of sharp climatic gradients. Forecasting HPEs depends on the ability of weather models to generate credible rainfall patterns. This paper characterises rainfall patterns during HPEs based on high-resolution weather radar data and evaluates the performance of a high-resolution, convection-permitting, Weather Research and Forecasting (WRF) model in simulating these patterns. We identified 41 HPEs in the eastern Mediterranean from a 24-year radar record using local thresholds based on quantiles for different durations, and we ran model simulations of these events. For most durations, HPEs near the coastline are characterised by the highest rain intensities, however, for short durations, the highest rain intensities characterise the inland desert. During the rainy season, the centre-of-mass of the rain field progresses from the sea inland. Rainfall during HPEs is highly localised both in space (

Evaluation of convection-permitting extreme precipitation simulations for the south of France

“…In particular, the CPSs can reproduce double rate of the Clausius-Clapeyron relation for the scaling of 3-hourly rainfall to surface temperature that is completely absent in the EUR-11 simulations with convection parameterized method and reproduce the high extremes in plain areas. These findings are coherent with other studies with convection-permitting approach forced by reanalysis data for other areas (Kendon et al, 2012;Armon et al, 2019;Ban et al, 2018;Knist et al, 2018;Fumière et al, 2019). We also find that the behaviour of CPS simulations is modulated by their driving GCM simulations given that they share the same regional climate model.…”