P90 The impact of model physics and upstream moisture sources on the May 2010 Tennessee flooding event: An examination of precipitation and surface hydrology

Mahoney, Kelly, Cooperative Institute for Research in Environmental Sciences

During 1–4 May 2010, heavy rainfall resulted in devastating flooding that caused 26 fatalities and $2–$3 billion in damages throughout Tennessee and Kentucky. 48-hour precipitation totals exceeded 400mm in some locations and all-time record water levels and discharges were observed at several river gauging sites. Using WRF and a number of new WRF applications such as the Mesoscale Model Evaluation Tool (MMET) and WRF-Hydro, this case is simulated in relatively high resolution (1 – 4km) in a series of sensitivity experiments. Model physics are perturbed to gauge sensitivity of two significantly different mesoscale convective systems that produced the heavy rainfall. Upstream moisture is also altered to assess the role of different moisture source regions in the resulting rainfall. WRF-Hydro is used to evaluate how precipitation translates to surface hydrology and flooding in the two main affected watersheds.