Understanding the processes that link the hydrology and the hydrometeorology of extreme floods is very important in the assessment of flood hazards. The study centers on empirical analyses of these fundamental physical processes that control the hydrology and hydrometeorology of extreme floods. A central premise is that high time/space resolution information concerning storm rainfall is central to advances in understanding flood response. The network of WSR-88D (Weather Surveillance Radar 1988 Doppler) radars provides the observational basis for obtaining a dramatic advance in measuring flood-producing rainfall.
Analyses of storm structure, motion and evolution are carried out from volume scan WSR-88D reflectivity and Doppler velocity observations for storms which produce flood peaks exceeding 100 year magnitude in the United States.
Flood hydrology is examined through WSR-88D rainfall products (at 6 minute time scale and 1 km grid scale) and discharge data at time scales ranging from 15 minutes to 1 hour.
Satellite imagery and ground-based raingage data are used to enhance storm evaluation. Events include the June and July 1996 flooding episodes from Iowa to Pennsylvania and the September 1996 large scale flooding associated with Hurricane Fran. These events produced 100 year flood peaks in multiple basins and allow for the analysis of hydrologic response to the space/time structure of rainfall at multiple basin scales.