B.C. is bracing for the king tides amid a stormy forecast

King tides are set to arrive along the coast of B.C. this week, but there’s trouble brewing with stormy conditions forecast.

Unsettled conditions will return to the South Coast region Friday night and continue through the weekend as a low tracks into northern Vancouver Island.

DON'T MISS: The science behind King Tides: What are they and how do they happen?

Tides are a regular fact of life for Canada's coastal regions. The waters along our shores advance and retreat twice every day.

Those tides also swell even higher and drop even lower twice every month, and there is even a longer cycle that requires a yearly calendar to track.

As part of the process, there is something known as king tides.

You need the sun and the moon to be in alignment as a necessary condition. Without that alignment, you wouldn’t get extreme tides.

The next most important factor is the moon’s closest approach to Earth. That is extremely important, and a classic ingredient in the king tide setup.

That is why not every full moon gives an equal tide, and during the moon's closest approach, you can get up to a 20 per cent stronger lunar forcing.

This next point is minor and more of a background boost. Earth is currently closest to the sun, but it’s the weakest effect of the three drivers. It only increases the tidal force by a few per cent, so it can’t be described as the primary driver.

Why B.C. experiences the king tides

Shallow coastal areas: Shallow bays and estuaries allow water to pile up more efficiently during peak tides

Long inlets and narrow fjords: Water is funnelled into long, confined inlets, which can locally raise water levels during high tides.

Timing matters: When king tides coincide with low pressure or strong, onshore winds, coastal flooding risk increases.

And this weekend, we have unsettled weather on the way that will bring gusty winds and larger wave heights.

Thumbnail courtesy of Arlene B., taken in Victoria, B.C.

With files from Tyler Hamilton, a meteorologist at The Weather Network, and Scott Sutherland, a science writer and meteorologist at The Weather Network.