Understanding the space-time scaling and dynamics of orographic precipitation and the development of upscaling and downscaling methods to transfer precipitation fields from one scale to another is the overall motivation for this research. Substantial progress has been made on characterizing the space-time organization of midwestern convective systems and tropical rainfall, which has lead to the development of statistical/dynamical downscaling models. Space-time analysis and downscaling of orographic precipitation has received much less attention due to the complexities of topographic influences.

A case study consisting of three consecutive orographic thunderstorms that occurred on June 27, 1995 in the eastern slope of the Blue Ridge Mountains of Virginia is examined from the perspective of relating the storms’ meteorological factors and underlying orography to the multi-scale structure of the rainfall fields. The statistical framework for this multi-scale characterization is cascade based and offers a parsimonious parameterization, which can be used in future studies for the purposes of stochastically downscaling rainfall fields. Sequences of radar derived rainfall maps provide data with which to characterize the multi-scale statistical structure and variability of the rainfall. In this case study, rainfall falling at higher altitudes was shown to be more intermittent and more organized than rainfall at lower altitudes. This trend is contrary to previous studies analyzing the multi-scale structure of orographic rainfall and is argued to be the direct result of differing meteorological factors for this type of storm such as the presence of warm rain processes and lee-side orographic forcing.