Timing is everything! Was it fortuitous that the moored buoy program of Environment Canada was established just in time to capture three extreme wave events in the early 1990's, or did that new data network simply reveal what was commonplace on the open seas?

Actually, timing wasn't that important in answering the question; it was answered through joint operationally-focused research and development work at Environment Canada's Hurricane Centre (CHC) and National Laboratory for Marine and Coastal Meteorology. The three storms which opened the eyes of meteorologists "The Perfect Storm" (1991), the "Storm of the Century" (1993), "Hurricane Luis" (1995) are now no longer seen as "record-mocking" outliers in an ocean of storm-wave data. Development of a working theory and an operational model for assessing storm-wave resonanceÑthe degree to which waves can continue to build while being contained in a moving storm systemÑhas led to routinely successful forecasts and the development of an extreme-wave climatology for Atlantic tropical cyclones. Both the theory and the model indicate that some of the highest ocean waves in the world occur in Atlantic Canadian waters when tropical cyclones undergo extratropical transition.

Coupled with operational experience in wave forecasting, CHC forecasters use a "trapped-fetch wave model" to assess when, where and how big will be the largest ocean waves with a tropical cyclone. The model's simple parametric approach allows for output in a matter of seconds, affording opportunities to use multiple wind models or make simple track perturbations in a real-time operational setting.

This presentation will explore the background to the CHC's interest in tropical cyclone waves, the operationally-based theory behind them, the "trapped-fetch" wave model, classic "resonance storms," and a glimpse at the recently developed climatology. And for Penn State University, it turns out that timing is everything after all less than a month before this presentation, Post-tropical Storm Noel hit Atlantic Canada with powerful ocean waves, giving a recent story to tell. The record-setting waves, in many ways worse than those experienced with Hurricane Juan (2003), resulted in severe and widespread coastal damage in Nova Scotia. Discussion of those waves along with images of the impacts will conclude the presentation.