title: The challenge of predicting flash floods from thunderstorm rainfall.
abstract: A major characteristic of the hydrometeorology of semi-arid regions is the occurrence of intense thunderstorms that develop very rapidly and cause severe flooding. In summer, monsoon air mass is often of subtropical origin and is characterized by convective instability. The existing observational network has major deficiencies for those regions in providing information that is important to run-off generation. Further, because of the complex interactions between the land surface and the atmosphere, mesoscale atmospheric models are currently able to reproduce only general features of the initiation and development of convective systems. In our research, several interrelated components including the use of satellite data to monitor precipitation, data assimilation of a mesoscale regional atmospheric model, modification of the land component of the mesoscale model to better represent the semi-arid region surface processes that control run-off generation, and the use of ensemble forecasting techniques to improve forecasts of precipitation and run-off potential are investigated. This presentation discusses our ongoing research in this area; preliminary results including an investigation related to the unprecedented flash floods that occurred across the Las Vegas valley (Nevada, USA) in July of 1999 are discussed.
authors.affiliation: National Science Foundation Science and Technology Center for Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA), Department of Hydrology and Water Resources, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Hosin
authors.initials: H
authors.lastname: Gupta
authors.forename: Soroosh
authors.initials: S
authors.lastname: Sorooshian
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Gao
authors.forename: Bisher
authors.initials: B
authors.lastname: Imam
authors.forename: Kuo-Lin
authors.initials: KL
authors.lastname: Hsu
authors.forename: Luis
authors.initials: L
authors.lastname: Bastidas
authors.forename: Jailun
authors.initials: J
authors.lastname: Li
authors.forename: Shayesteh
authors.initials: S
authors.lastname: Mahani
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003889:Desert Climate; D004190:Disasters; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D005544:Forecasting / Q000379:methods*; D008962:Models, Theoretical; D009505:Nevada; D011891:Rain; D015203:Reproducibility of Results; D017215:Satellite Communications; D012621:Seasons; D012680:Sensitivity and Specificity; D015206:Southwestern United States; D018511:Systems Integration