The flooding of Hurricane Ivan: How far ahead can we predict?

On September 16, 2004, Hurricane Ivan (by then a tropical depression) made its way across Western North Carolina, bringing with it large amounts of heavy rainfall. The Swannanoa River watershed, still not recovered from the rainfall of Hurricane Francis just two weeks before, was overburdened and several places, most notably the Biltmore area, became flooded under several feet of water.

In order to handle such events in the future, NEMAC (the National Environmental Modeling & Analysis Center) in Asheville, North Carolina is working in cooperation with RENCI (Renaissance Computing Institute) to better understand these weather events and develop a disaster response and mitigation system. As my part of this project, I will be trying to judge the accuracy of the WRF (Weather Research and Forecasting) Model in relation to flood-producing storm events in the Swannanoa watershed. To do this I will be modeling Hurricane Ivan. Using observed starting conditions, I will run four simulations, one at each of 24, 36, 48, and 60 hours before the period of maximum rainfall for the Swannanoa area. By comparing the output of each of these simulations against the observed rainfall amounts, I will determine how far in advance the model is able to accurately judge the severity of the storm system. This knowledge, when integrated with other parts of the RENCI project and applied to similar storms in the future, will be invaluable to both the general public and those in charge of disaster response alike.