Modelling of waves and set-up for the storm of 11-12 January 2005

Abstract On 11-12 January 2005 a severe storm hit the Outer Hebrides and there was flooding on the islands of South Uist and Barra, caused by storm surge and waves. Five lives were lost in one family as they attempted to cross a causeway near Balgarva on South Uist in two cars. Here we investigate the magnitude of the local wave height and the associated wave set-up which caused an additional increase in water level above that due to the astronomical tide and storm surge, using a suite of nested wave models. Wave data from buoys and altimeter are used to validate the model. The wave set-up was found to be nearly 0.5m due to the proximity of exceptionally high waves reaching over 14m less than 50km offshore.