Convection in future winter storms over northern Europe.

Abstract:

Met Office convection-permitting 2.2km simulations over both a European domain show 10-20% larger increases in winter mean precipitation than their 12km/25km convection-parameterised driving models. We identify individual storms with a maximum vorticity tracking algorithm and look at storm characteristics at their time of deepest minimum sea level pressure. We show that thermodynamical characteristics of future winter depressions are getting closer to present-day autumn storms. Future winter storms show more moderate rainfall in the dry intrusion and warm frontal sector, and more intense rainfall in the warm conveyor belt. The better representation of embedded convection and slantwise convection in the 2.2km may lead to a larger intensification of rainfall per storm in the 2.2km model in the future.