A Parametric Rainfall Model, P-CLIPER: Development and Application for Coastal Flood Modeling

During tropical storms, rainfall can lead to a significant amount of flooding, both in the upland and coastal areas. A coupled modeling system was developed to provide total water level (tides + waves + surge + runoff) results. The system couples precipitation estimates via QPE/QPF (Quantitative Precipitation Estimation/Forecasting), a hydrologic model (HL-RDHM – Research Distributed Hydrologic Model), a hydrodynamic model (ADCIRC – ADvanced CIRCulation) and a wave model (SWAN – Simulating WAves Nearshore). It was successfully utilized during Hurricane Irene in 2011. However, the precipitation estimates via QPE/QPF are only associated with the direct track of the hurricane. Thus, as an extension of this work we investigated a parametric rainfall model in order to be able to incorporate ensemble capability into the precipitation estimates term. For example, the rainfall estimate produced by NOAA in the current system is only associated with the consensus track of the hurricane from the National Hurricane Center; by incorporating the new parametric rainfall model, the rainfall associated with different hurricane tracks could be included. In this presentation, we will summarize the development of a parametric rainfall model, PDF Precipitation-Climatology and Persistence (P-CLIPER). Several historical hurricane storms within the North Carolina area will be utilized in the evaluation of P-CLIPER. Skill is assessed by direct comparison to observed precipitation and by comparing the hydrological response of model driven by P-CLIPER versus observed precipitation estimates.