Atmospheric Rivers (ARs) are important sources of moisture in the Western United States. Inland-penetrating ARs influence the microphysics and dynamics of orographic clouds leading to precipitation in this region. As the inland west is experiencing a long-standing drought, insight into the proces... Show moreAtmospheric Rivers (ARs) are important sources of moisture in the Western United States. Inland-penetrating ARs influence the microphysics and dynamics of orographic clouds leading to precipitation in this region. As the inland west is experiencing a long-standing drought, insight into the processes that bring moisture to the west will provide for a greater understanding of future precipitation and drought conditions. The region of focus for this study is the Payette River Basin in Idaho. Data from the Atmospheric River Tracking Method Intercomparison Project (ARTMIP) was used to identify ARs and quantify their strength. Two ARTMIP Atmospheric River Detection Tools (ARDTs), which provided the most coverage for inland areas, were chosen for this analysis. The Seeded and Natural Orographic Wintertime clouds: the Idaho Experiment (SNOWIE) project (January - March, 2017) provided aircraft-based radar and in-situ microphysics data and radiosonde thermodynamic data. The connection between ARs and the microphysics and dynamics of orographic clouds was investigated in a case study using SNOWIE flight (IOP)12 (February 7, 2017). This IOP was chosen because ARTMIP data strongly indicated the presence of an AR in the study area and because it was unique in that the cloud structures observed included orographic and highly convective clouds. Sounding data before and during the IOP showed that an incoming AR noticeably influenced the thermodynamics in IOP12. An increase in moisture was observed which led to an increase in atmospheric instability. The increased instability induced elevated convection by providing extra lift than would have occurred from the orographic process alone. Analysis of the in-situ microphysics data showed very low cloud droplet concentrations and mixed phase conditions in the convective clouds. Outside of the convection, shallow orographic cloud tops were mostly liquid and contained supercooled drizzle. The difference in conditions between the orographic and convective clouds led to our conclusion that the convection enabled enhanced precipitation formation processes that may not have occurred in the shallow, warmer orographic clouds. Future research will include analysis of all 24 SNOWIE IOPs and all ARTMIP ARDTs for inland penetrating ARs to build upon the findings in this study. Show less