High-Resolution Mesoscale Simulations of the 6-7 May 2000 Missouri Flash Flood: Impact of Model Initialization and Land Surface Treatment

摘要

High-resolution mesoscale model simulations of the 6-7 May 2000 Missouri flash flood event were performed to test the impact of model initialization and land surface treatment on timing, intensity, and location of extreme precipitation. In this flash flood event, a mesoscale convective system (MCS) produced over 340 mm of rain in roughly 9 hours in some locations. Two different types of model initialization were employed: (1) NCEP global reanalysis with 2.5-degree grid spacing and 12-hour temporal resolution, and (2) Eta reanalysis with 40- km grid spacing and 3-hour temporal resolution. In addition, two different land surface treatments were considered. A simple land scheme (SLAB) keeps soil moisture fixed at initial values throughout the simulation, while a more sophisticated land model (PLACE) allows for rainfall-soil moisture interactive feedback.