Key Factors Influencing Snowfall Structure in the Mid‐Eastern Region of the Korean Peninsula: An Idealized Numerical Study

Abstract

In the Gangwon region of the mid‐eastern Korean Peninsula, snowfall commonly occurs during winter under easterly winds associated with the Siberian High. This high‐pressure system induces cold and dry easterlies over the East Sea, which gain heat and moisture, enhance thermal instability in the lower troposphere, and promote the formation of convective cloud rolls. As these moist easterlies move inland and ascend the coastal mountains due to orographic forcing, snowfall is generated. Snowfall is influenced by multiple factors, including topography, synoptic conditions, and sea surface characteristics. This study focuses on four key factors affecting snowfall structure—air‐sea temperature difference, wind turning layer (WTL) height, Froude number (FN), and horizontal temperature contrast between land and sea—using idealized Weather Research and Forecasting (WRF) model experiments. Each factor was isolated by keeping the other parameters constant. The results show that an increased air‐sea temperature difference enhances precipitation primarily over the sea, whereas a strong horizontal temperature contrast between land and sea restricts inland precipitation transport. Higher WTL height and FN values exceeding 0.6 promote precipitation advection, allowing snowfall to reach the mountaintop. In contrast, when the WTL is located below the mountain height, inland precipitation advection is limited. This study investigates how thermodynamic and dynamic factors affect snowfall structures over the topography of the Gangwon region and identifies the inland snowfall transport characteristics associated with threshold values of these key factors.