Topographic and atmospheric influences on precipitation variability over a mountainous watershed

Examination of orthogonal spatial patterns of daily and monthly precipitation on a mountainous watershed in Idaho by rotated principal component analysis helps derive the influence of topography, geographic location and atmospheric variability on the spatial patterns. Regional boundaries derived from monthly data exhibit close alignment with topography, suggesting the integration of various storm events on monthly timescales. Topography and geographic location exhibit significant correlation with spatial fields. Data from a single location is enough to predict spatial pattern changes and regional precipitation fluctuation, provided sufficient knowledge about local climate is available.