Space-time rainfall organization and its role in validating quantitative precipitation forecasts

The scope of this paper is to introduce a suite of new multiscale statistical measures which can be used, in addition to traditional measures, to compare observed and model-predicted patterns for model validation. Recent research on analysis of observed precipitation patterns at a multitude of scales has revealed interesting spatial and spatiotemporal organizations which have often been related to physical properties of the storm environment. By testing whether this multiscale statistical organization is also reproduced in the model-predicted patterns or whether there are significant biases and disagreements in such comparisons is conjectured to hold promise for understanding model performance and guiding future model improvements. Results from application of the developed methodologies to the May 7-8, 1995, multisquall line storm over central Oklahoma are presented and discussed in light of the additional information gained by the new validation measures as compared to traditional measures.