Low-level jets (LLJs), streams of fast-moving air in the lower atmosphere, have a strong impact on the weather and climate of the Great Plains of the United States. Southerly LLJs are known to play an important role in transporting moisture and heat from the Gulf of Mexico northward and are primarily responsible for the summertime nocturnal convection in the Great Plains region, whereas Northerly LLJs have been linked to blizzards and large spread of wildfires. While numerous studies have examined the properties and forcing mechanisms of southerly LLJs, little is known about the formation and characteristics of the NLLJs. In this study, we apply the Weather Research and Forecast (WRF) model to simulate two historical cases of a well-developed NLLJ. The purpose is to improve the understanding of the structure and evolution of NLLJ and the large-scale and local atmospheric environments in which they form. The WRF model is configured with multiple nested grids and is initialized using the North American Regional Reanalysis (NARR). The simulation results are compared with both surface and upper-air observations. Simulations were performed with different model physical parameterizations and process analyses are performed to help identify important factors important for the formation of the NLLJs.
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