Comparison of extreme precipitation event representation between models in a northern Europe case study

This study compares the representation of extreme precipitation events between a 2.2km resolution Convection Permitting Model (CPM) and a 12km Regional Climate Model (RCM) from the UK Met Office over a pan-European domain from 1999-2008. The tracking algorithm DYMECS is applied to the data (which has been regridded to a common 12km grid), to compare evolution in size and intensity, and the spatial and temporal occurrence of extreme events between the two models.

Extreme events within a northern European case area are categorised in terms of maximum intensity and maximum size reached within their lifetime. The CPM and RCM data show disagreement in the spatial distribution, movement direction and seasonal occurrence of maximum intensity storms. On the other hand, the two models show good agreement in both the spatial and seasonal distribution of the largest storms in terms of spatial area.

A comparison with the COSMO REA6 reanalysis model with continuously nudged observations, suggests that the CPM performs better in capturing the spatial and seasonal distributions of the maximum intensity storms. The study concludes that the CPM seems to improve the representation of extreme events in terms of their spatiotemporal characteristics, with more realistic intensities.