Future precipitation increase from very high resolution ensemble downscaling of extreme atmospheric river storms in California

• DOI: 10.1126/sciadv.aba1323
• Publication Date: 2020-07-15T23:15:39Z
• Authors: Xingying Huang; Daniel L. Swain; Alex D. Hall
• Keywords: Climate extremes

Precipitation extremes will likely intensify under climate change. However, much uncertainty surrounds intensification of high-magnitude events that are often inadequately resolved by global models. In this analysis, we develop a framework involving targeted dynamical downscaling historical and future extreme precipitation produced large ensemble model. This is applied to "atmospheric river" storms in California. We find substantial (10 40%) increase total accumulated precipitation, with the largest relative increases valleys mountain lee-side areas. also report even higher more spatially uniform hourly maximum intensity, which exceed Clausius-Clapeyron expectations. Up 85% arises from thermodynamically driven water vapor, smaller contribution increased zonal wind strength. These findings imply challenges for flood management California, given intense atmospheric river-induced extremes.