Performance of a nested regional spectral model coupled with a mesoscale model under contrasting ENSO regimes

The difficulty of application of climate modeling results to regions with significant mesoscale variability and dynamics has stirred interest in both dynamical and statistical methods of climate model "downscaling". To investigate the impacts of large-scale sea surface temperature variations such as ENSO on local climatological phenomena (such as sea breeze thunderstorms), a version of the FSU Nested Regional Spectral Model (FSUNRSM) is being developed which may be coupled to a nested non-hydrostatic mesoscale model (MM5). First we will describe results from seasonal forecasts with the FSUNRSM using observed sea surface temperatures from years of contrasting ENSO signal. Then the potential of a nested non-hydrostatic model within the FSUNRSM to provide added value for downscaling of seasonal impacts along coastal zones and in regions of complex topography will be explored. Preliminary examples will be shown from cases over the Mississippi Gulf Coast region. A brief description of the mesoscale meteorology of the region will be given, based on other modeling and observed conditions, to provide context for the potential value of such an approach to including non-hydrostatic dynamics in a seasonal forecasting model.