Numerical Simulation of a 4-Day Early Spring Storm Period in the Black Hills

Abstract

This paper illustrates the potential for mesoscale models to depict the distribution of precipitation in orographic situations. The study covers a 4-day time period in April 1995. The domain of the numerical model covers much of western South Dakota and some of eastern Wyoming and is centered on the Black Hills of South Dakota. The 4-day storm period is characterized by changing atmospheric conditions, from primarily rain generation to snowfall production. Observations and climatic data of precipitation are analyzed to compare with model predictions. The model demonstrated the ability to respond appropriately to changing input conditions and produced reasonably accurate simulations of observed precipitation patterns. The model performed well for sufficiently cold, strongly forced conditions but seemed overly sensitive to the accuracy of model assumptions regarding ice initiation for warmer, weakly forced situations.