Estimation of Ground Snow Loads for Low-Latitude, High-Elevation Regions

The mountainous regions of the southern United States experience substantial snow loads. This study develops a data-driven method for determining 50-year ground snow load (GSL) in high-elevation, low-latitude regions and applies it to Coconino County, Arizona. A new relationship between snow depth and GSL is developed, as applying a relationship developed for the entire United States would result in an underestimation of GSL. The peaks-over-Threshold method provided a reliable alternative to the commonly used annual maxima method to determine GSL at stations with short or incomplete data records. Simple kriging with locally varying means was used to spatially model GSL in the region, which is strongly controlled by elevation with variation around topographic features. The effect of elevation was not accurately represented in the current ground snow loads prescribed by Coconino County, leading to values that are too high for lower-elevation areas and too low for higher-elevation areas.