Developing new and improved numerical models is critical for advancing the state of the science, improving weather prediction, and better understanding future climate, all of which are currently being explored at the University of Wyoming (Lebo and Liu). The model development research in the department of Atmospheric Science can largely be broken into cloud-scale microphysics and dynamics as well as long-term climate. Current efforts are underway to improve the representation of snow formation in regional-scale numerical models, e.g., the Weather Research and Forecasting (WRF) model, which is essential for the prediction of snowfall in winter storms. We are also looking at new ways to represent the complex growth and melting of hailstones to better inform severe weather forecasters and are continuing to improve current numerical models with novel numerical approaches. On the climate scale, the research efforts are focused on developing and improving aerosol and ice nucleation schemes in the Community Earth System Model (CESM) and the Goddard Earth Observing System Model version 5 (GEOS-5). New work is centered on assisting in the development of the Accelerate Climate Model for Energy (ACME) and better understanding the impacts of biomass burning on climate.