A new view of heat wave dynamics and predictability over the eastern Mediterranean

Abstract. Skillful forecasts of extreme weather events have a major socioeconomic relevance. Here, we compare two complementary approaches to diagnose the predictability weather: recent developments in dynamical systems theory and numerical ensemble forecasts. The former allows us define atmospheric configurations terms their persistence local dimension, which provides information on how atmosphere evolves from given state interest. These metrics may be used as proxies for intrinsic atmosphere, only depends atmosphere's properties. Ensemble provide practical partly performance model used. We focus heat waves affecting eastern Mediterranean. are identified using climatic stress index (CSI), was explicitly developed summer conditions this region differentiates between (upper decile) cool days (lower decile). Significant differences found groups both prediction perspectives. Specifically, show relatively stable flow characteristics (high predictability) but comparatively low (large spread error). For 500 hPa geopotential height fields, is lowest at event's onset decay. relate these results physical processes governing Mediterranean waves: adiabatic descent air parcels over geographical origin land prior wave. A detailed analysis mid-August 2010 record-breaking wave further insights into range different regional conducive waves. conclude that approach can useful complement conventional understanding dynamics