Abstract/Summary

Leveraging the novel kilometer-scale global storm-resolving model GFDL X-SHiELD, we investigate the impact of a 4 K increase in sea surface temperatures on Northern Hemisphere midlatitude cyclones, over a three-year-long period. X-SHiELD simulations show a poleward shift in midlatitude cyclone tracks under +4 K warming, consistent with CMIP model projections. Thanks to X-SHiELD's high resolution and explicit deep convection, we provide a detailed analysis of the warm and cold sectors of midlatitude cyclones, which are typically underrepresented in coarser CMIP models. Compositing the 100 most intense midlatitude cyclones in the North Atlantic, we find that the warm sector exhibits wind speed and precipitation increases of up to 15% and 20% per degree of warming, respectively, while changes in the cold sector are less pronounced. This study demonstrates X-SHiELD's potential to provide a realistic-looking picture into the evolving risks posed by midlatitude cyclones in a warmer world. Plain Language Summary In this study, we use a cutting-edge global storm-resolving model called GFDL X-SHiELD to understand how intense storms, known as midlatitude cyclones, might change as the climate warms. Specifically, we examine how a 4 degrees Celsius increase in sea surface temperatures affects these storms in the Northern Hemisphere over a three-year period. Our simulations show that the tracks of midlatitude cyclones tend to shift toward the poles as temperatures rise, which is consistent with previous climate model projections.