Nfld. & Labrador

Dorian kicks up more than one monster wave near Port aux Basques

As post-tropical storm Dorian moves its way north of Newfoundland and Labrador data is rolling in on how powerful the storm really was.

Several waves exceeded 25 metres

Bill Carter is the director of CTec, the team behind the technology which recorded waves of up to 30 metres as post-tropical storm Dorian swept over Newfoundland and Labrador. (Gary Locke/CBC)

As post-tropical storm Dorian moves its way north of Newfoundland and Labrador data is rolling in on how powerful the storm really was.

According to the Washington Post, which tracked the storm north of the United States, a Marine Institute-owned buoy picked up a massive rogue wave that topped 100 feet, just over 30 metres, roughly 2.4 kilometres off of the coast of Port aux Basques. That's about the equivalent of an eight-storey building.

"It measures the acceleration and deceleration of the buoy as it travels up and down on the waves, and from that does a calibration of what the wave height might be," said Bill Carter, director with the Centre for Applied Ocean Technology, the team responsible for the equipment which picked up the 30-metre monster.

But more than that, Carter said there were many big recordings on Sunday, several of which broke 25 metres and many more which broke 20 metres in height.  

The three-metre buoys are equipped with accelerometers which calculate the time of the rise and fall of the buoy through a wave to determine the height,.

Through significant wave height, it measures the highest third of the wave.

It also measures wind speed, barometric pressure, dew points and wave direction.

Even bigger?

The buoys collect data in 20 minute blocks, every 30 minutes. 

Carter said the 30-metre data was collected in only one of those blocks, while other blocks recorded data at 25 metres and higher, with many more coming in at 20 metres. He added there may have been bigger recordings while the buoy wasn't recording data.

CTec's weather buoys are anchored to the ocean floor where they collect data on wave speed, wave height, barometric pressure and dew point. (Gary Locke/CBC)

However, Carter is quick to admit that he's only the man behind the equipment.

"I can't speak to the accuracy of this, nor can I speak that this is even possible in the area. I am not an oceanographer. I'm a technical guy who keeps this kind of stuff going," he said.

"But I can say that our equipment was installed correctly, all of our instrumentation was calibrated and our buoy ran for that full period, and continues to run, and is functioning now quite accurately."

Building up

"It appears that this was measured with storm Dorian as it was moving up toward the island of Newfoundland just a little ways offshore from Port aux Basques," David Neil, a meteorologist with the Gander weather office told CBC Radio's St. John's Morning Show

Emergency crews respond Sunday to a power line downed in Corner Brook. ( Lindsay Bird/CBC)

Neil said big waves are to be expected in hurricanes and tropical storms, but only predicted them to reach between 10 and 15 metres as Dorian made its way over Newfoundland and Labrador. 

While a wave of 30 metre magnitude isn't common, Neil said it's always plausible. 

The meteorologist said it generally takes a combination of naturally occurring events during a storm to have waves reach 75 to 100 feet.

"With the wave heights that were coming in that were quite high, if you get a few of those waves together they can build up constructively," Neil said. 

"Of course as it interacts with some of the more shallow coastal waters you can get some buildup of height there. It does take a good setup, but it isn't out of the question."

Southwestern Newfoundland was the area likely to see the highest waves and water levels during Sunday's storm, according to Neil. As of Tuesday, he said, there had been no reports of major problems.

Read more from CBC Newfoundland and Labrador

With files from The St. John's Morning Show


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