Convective and stratiform precipitation trends in the Spanish Mediterranean coast

Eastern Iberian Peninsula is characterized by the large occurrence of convective precipitation events, which entail important economic and social damage consequences. In order to prevent and minimize its effects, a good knowledge and understanding of the meteorological processes involved are necessary to be achieved. In this regard, an algorithm for classifying convective and stratiform precipitation components has been applied to a decadal precipitation record.Dataset were provided by National Spanish Meteorological Agency (AEMET) for the period 1998–2008. Hourly precipitation records have been analyzed. The goals of this study have been: a) to classify total precipitation into its stratiform and convective components in Levante region (located in the Eastern Spanish Coast) and b) to analyze annual and seasonal trends of such components.For determining both convective and stratiform precipitation components, a suitable exponential function has been used. After a computation process, critical precipitation intensity (so-called Rc) is obtained for each year and season of the studied period. Every precipitation episode in Levante region is classified into prevailing convective or stratiform regime according to the threshold value defined by Rc.The results obtained have been compared to Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA-COARE) to verify the validity of the algorithm. First results show an annual and seasonal significant positive trend in total precipitation and stratiform component for 1998–2008 decade. Further analysis reveals that convective precipitation exhibits no significant trend. Preliminary conclusions state that the total precipitation amount in Levante Region strongly depends on the stratiform component evolution.

► Different rainfall types in the West Mediterranean for a decade have been studied.
► Annual results show that precipitation increases mainly due to stratiform component.
► Seasonal results exhibit that the convective one dominates in summer and autumn.
► Similar evolution is observed in comparison to TOGA Project data.