The Weather Research and Forecasting (WRF) model is a mesoscale numerical weather prediction model designed for both atmospheric research and operational forecasting applications across scales ranging from large-eddy to global simulations. The Advanced Research WRF (ARW) features a dynamical core that solves the fully compressible non-hydrostatic equations using terrain-following hydrostatic-pressure vertical coordinates and the Arakawa C-grid staggering spatial discretization for variables (Skamarock et al., 2008). Different versions of ARW have been used in regional climate modeling, including simulations that contributed to the North American Regional Climate Change Assessment Program (NARCCAP) and the North America Coordinated Downscaling Experiment (NA-CORDEX).

WRF is used to dynamically downscale climate data to a higher resolution over regions of interest. Within IM3, WRF is used to downscale ERA5 reanalysis data and climate change signals from multiple GCMs to a horizontal resolution of 12 km over the entire CONUS. Within IM3, WRF-UCM (single layer urban canopy model) is used to reproduce urban micro-climate dynamics as well as to downscale climate information over cities of interest at resolutions of up to 500 m that are relevant to urban processes. WRF-UCM is capable of producing numerous outputs that represent urban micro-climate/weather/meteorological conditions. WRF is capable of producing numerous outputs that represent the climate/weather/meteorological conditions. Within IM3, WRF is used to produce climate variables that are required to force other models such as near surface and surface temperatures, humidity, wind speed and direction, precipitation, etc.