Characteristics of Wintertime Precipitation in Two Western Wyoming Mountainous Regions

Abstract:

High-resolution (4 km grid spacing) climate simulations using the Weather Research and Forecasting (WRF) model have been run to study precipitation over the Colorado Headwaters region. These simulations have also been used to study the behavior of wintertime precipitation over two mountainous regions in western Wyoming: the Salt River and Wyoming Ranges, which are a set of narrow, north-south oriented mountains nearly parallel to one another, and the Wind River Range, which is oriented from the northwest to southeast extending into central Wyoming. The simulations have been compared against SNOTEL precipitation gauge measurements, which has shown that at most SNOTEL sites the WRF simulations represent the precipitation quite well. This paper will present the results of the model and SNOTEL gauge analysis, as well as compare and contrast the behavior of precipitation between the two regions. Of note are the differences in the importance of an easterly upslope precipitation wind regime between the regions, and the potential for cloud seeding in each region given the presence of supercooled liquid water in the orographic clouds.