Numerical simulation of extreme waves during the storm of 20–22 January 2000 using winds generated by the CMC weather prediction model

Abstract

The storm of 20–22 January 2000 over Canada's Atlantic Provinces was an exceptional storm for several reasons, these include extremely high coastal ocean waves, widespread coastal damage due to the storm surge, very strong winds over a large area, an extremely fast deepening rate, and a very low central pressure. It produced unusually large waves which caused significant damage in communities along the south coast of Newfoundland and the eastern shores of Nova Scotia. Bottom scouring was observed around the feet of three mobile offshore oil and gas drilling platforms operating near Sable Island. Using buoy data enhanced with a detailed data set from one of the platforms, this study examines the growth of destructive waves and the performance of two state‐of‐the‐art third generation ocean wave models running in shallow water mode. The wave models perform well in numerically simulating the extreme waves associated with this storm. They correctly predict the growth of wind waves and handle the arrival of long‐period swells well. Unprecedented waves that damaged buildings and a lighthouse in the Channel Head area of Port‐Aux‐Basques retained most of their deep‐water energy until they were less than one wavelength from the beach. Computations show that dynamic (or trapped) fetch was not a contributing factor in the generation of the observed extreme sea states although the long‐period swells were supported by winds for a significant part of their transit northward. However, it appears that the model‐generated enhanced wave growth at the buoy location just off the southwestern coast of Newfoundland may be partially linked to the creation of model trapped fetch. The January 2000 storm was indeed an extreme storm and was the most intense non‐tropical storm to form over Atlantic Canada in decades.