Large Eddy Simulations Over the S2noCliME Field Campaign Domain: A Case Study over the Park Range

The U.S. Mountain West faces increasing challenges due to warming temperatures and declining snowpacks, with notable increases in rain-on-snow events. To improve our understanding of cold-season cloud and precipitation processes in these regions, the Snow Sensitivity to Clouds in a Mountain Environment (S²noCliME) Field Campaign, funded by NSF, will take place during the 2024-2025 winter season in the Park Range of Northwest Colorado. This field campaign will utilize a combination of ground-based, remote sensing, and in situ measurements to investigate orographic influences on cloud and snowfall processes.

This study focuses on the application of Large Eddy Simulations (LES) using the Weather Research and Forecasting (WRF) model to capture fine-scale flow features associated with clouds and precipitation during a winter storm over the Park Range sampled on 15 December 2010 during the Storm Peak Lab Cloud Property Validation Experiment (StormVEx). Initial simulations have been conducted to identify optimal model configurations, including domain size, resolution, and physics parameterizations. LES modeling will be used to provide high-resolution insights into the interaction between large-scale environmental conditions and local terrain-induced effects on snowfall distribution.

The results highlight the model’s ability to replicate observed cloud and precipitation structures, as well as to provide detailed context for the field campaign observations. Specifically, the LES model captures the vertical and horizontal variability in updrafts, downdrafts, and shear layers that are crucial for understanding snow generation and distribution over complex terrain. These simulations will be essential for improving predictive capabilities in mountainous regions facing changing climatic conditions.