Wild waves can happen at any time

Re: “Near-drowning in Ucluelet prompts warning to stay on trails during storm season,” Sept. 28.

The large wave that caught Ucluelet residents unaware last Wednesday is another important reminder that individual extreme ocean waves can occur at any time, even in apparently safe conditions high on the beach.

During a storm, one should expect at least one or two waves twice as high as the average “high waves.” In some conditions, these extreme waves can occur more than 10 times in a day.

These are the events that get media attention when they cause human harm or damage to ships, or coastal and offshore structures. But it is not only the extreme large waves that might be dangerous.

The sea state fluctuates naturally, and might sometimes appear deceptively calm, only to be interrupted by a wave that is perhaps twice as big as any of the waves in the previous several minutes.

These “unexpected waves” do not have to be large compared to the typical waves in the storm, but might surprise someone wandering close to the water’s edge.

Understanding and predicting these extreme ocean waves has been a longtime research focus of the Ocean Physics group at the University of Victoria.

The exact timing of such a wave is uncertain, but we now understand the conditions when they are most likely. We are developing predictions of hazardous wave conditions for the Pacific Rim National Park and Tofino in collaboration with Parks Canada.

Our wave forecast model for the entire west coast of Canada will be implemented at Environment and Climate Change Canada later this year.

These predictions will be available to the public, and our hope is that they help keep beachgoers dry and safe.

Johannes Gemmrich, PhD University of Victoria