ARkStorm 2.0 is a cross-disciplinary flood emergency management and climate adaptation scenario aimed at quantifying and ultimately mitigating the consequences of "plausible worst case" flood scenarios in California in a warming climate. It builds upon previous disaster contingency and emergency response planning efforts--including the original ARkStorm exercise (ARkStorm 1.0), which was completed in 2010. In ARkStorm 2.0, we update and upgrade the methods used in ARkStorm 1.0 in two key ways: 1) by incorporating, for the first time, the influence of climate change, and 2) by using a systematic, physically-based approach to scenario event selection. To do so, we conduct new simulations by embedding a high-resolution weather model, the Weather Research and Forecasting Model (WRF), within initial and boundary conditions from an existing climate model large ensemble (CESM-LENS). The data included in this DesignSafe project includes initial condition, forcing, and configuration files for Weather Research and Forecasting Model (WRF) simulations used to develop the hypothetical extreme storm scenarios in ARkStorm 2.0. It also includes WRF output files containing various meteorological variables (including, but not limited to, precipitation, wind, snow water equivalent, and surface runoff) discussed in Huang and Swain 2022 that may be of interest in characterizing natural hazard impacts in the context of the underlying scenario. These data are intended to be widely used and reused in the development of meteorological scenarios, hydrologic simulations, risk assessments, and other activities aimed at quantifying and mitigating natural hazard risk in California stemming from extreme winter storms in a warming climate. Additionally, those interested in conducting follow-on research specifically based on the published ARkStorm 2.0 scenarios may use the data stored here as boundary/initial conditions to conduct new simulations regarding floods, debris flows, landslides, coastal inundation, or other geophysical hazards that might result from extremely heavy precipitation due to atmospheric river storms in California.