Exploring the particularities of the method object-based in the precipitation forecast evaluation

Abstract

Numerical Weather Prediction Models (NWPM) are based on computational methods applied to predict meteorological phenomena from the numerical integration of equations that describe the movement of the atmospheric components. Among the variables predicted by NWPM, precipitation is one of the most important, and it is also the most difficult to obtain good results in the positioning, intensity, and extension of the events. One of the sources of uncertainty in the quality of these forecasts is the evaluation method because conventional methods do not evaluate the spatial aspects appropriately. The objective of this study is to propose and validate a methodology of object-based diagnostic evaluation using Object-Based Diagnostic Evaluation (MODE) algorithm implemented in the Community System for the Evaluation of Numerical Models of Weather and Climate Prediction (SCANTEC). Experiments using idealized cases are presented, which allow validate the implementation of the method and show its advantages over conventional evaluation metrics. The results of this method are also presented in the comparison of the real precipitation forecasts generated by routinely used models in CPTEC as proof of concept, exemplifying its use to explore the available metrics. The results demonstrate the great potential of the object-based methodology for the evolution of the NWPM.

Keywords:
spatial verification methods; object-based evaluation; SCANTEC; precipitation forecast evaluation