Tuesday, 18 July 2023: 5:00 PM
Madison Ballroom B (Monona Terrace)
C-SHiELD is a global-nested storm-resolving model designed to predict severe weather over the contiguous United States (CONUS). It is one configuration of the System for High-resolution prediction on Earth-to-Local Domains (SHiELD), an FV3-powered unified modeling system for weather-to-subseasonal prediction developed at the Geophysical Fluid Dynamics Laboratory. C-SHiELD features a global-nested grid: a 3-km nest domain over the CONUS within a 13-km global model, a cost-effective way to bridge the gap between storm-scale and planetary-scale dynamics. Unlike regional models, C-SHiELD can explicitly resolve convective storm activities over the CONUS while capturing the general circulation, enabling medium-range and even subseasonal prediction of severe weather for the CONUS. Taking advantage of the unified modeling approach, C-SHiELD builds upon advances in other configurations of SHiELD (global, regional, tropical-nest, etc.) and improves over time. We will present recent developments of C-SHiELD. We will show C-SHiELD has forecast skills comparable to or better than operational regional and global models, and can predict severe weather outbreaks on medium-range timescales. We evaluate the performance of C-SHiELD by examining both storm-scale and synoptic-to-planetary scales. On storm-scale, we assess the organization and propagation of simulated storms and associated environmental characteristics. On synoptic-to-planetary scales, we assess measures of the spatial organization of planetary waves and their impact on the atmosphere structures. We will also show the potential of C-SHiELD for subseasonal severe weather forecasts. More information about SHiELD, including real-time forecasts, codes, and data, can be found at www.gfdl.noaa.gov/shield.

