Above: Lonnie Snow photo
While the 2023 hurricane season is predicted to be an overall average one, the Canadian Hurricane Centre (CHC) warns that Atlantic Canada only needs one large storm to see a repeat of the catastrophic 2022 Hurricane Fiona.
The National Oceanic and Atmospheric Administration (NOAA) has predicted there will be a 70 per cent chance that the Atlantic Ocean will see between 14 to 21 named storms, of which six to 11 could become hurricanes. Of those six to 11 hurricanes, around two to five have a chance of becoming category three or higher hurricanes.
According to Bob Robichaud, a warning preparedness meteorologist with the CHC, it is hard to tell how these predictions will play out and how they will affect Atlantic Canada until the storms have actually formed over the Atlantic.
“What they actually issue is the number of storms that are expected to form in the Atlantic — the entire basin — over the course of the season, not necessarily where these storms are going to go,” said Robichaud. “Really, we have to wait until the storm has actually formed to have an idea as to where they’re going.
The CHC has a “response zone,” which extends 200 kilometres from their marine district. According to Robichaud, a fraction of storms that form within the Atlantic actually fall within this response zone. Even fewer of these storms make landfall in Atlantic Canada, with only Hurricane Fiona — one of eight hurricanes — making landfall in Canada in 2022. Given the predictions for the 2023 season, about three to four storms are expected to make their way into Canada’s response zone.
“On average, we get about 35–40 per cent of the storms that actually form in the Atlantic finding their way into Atlantic Canada,” said Robichaud. “That can range from anything that’s tracking over the Grand Banks and may not have an impact on land, or it could be a landfalling storm… About three to four would enter our response zone; maybe one or two would have some sort of impact on land on an average season.”
Currently, the benchmark for what makes “normal” hurricane season is about 14 storms. With 14–21 storms predicted this year, 2023 stands to be a “near-normal” or “above-normal” hurricane season. This benchmark, according to Robichaud, is reassessed every decade to adjust for a change in averages. Since 1991, the average has held at around 14 storms.
Whether predictions call for a normal or a busy hurricane season, the CHC advocates for the same level of emergency preparedness every year.
“It only takes one storm to make it a bad year, so we’ve got to prepare for the one single storm that can have a huge impact,” said Robichaud. “Last year is a good example of that with Fiona. We had only one storm made landfall in Canada last year, but it was a doozy with Fiona.”
When it comes to preparing for a storm, Robichaud encourages anyone in possibly affected areas to assess their vulnerability to inclement weather.
“The first thing for people to do is to pause and look at what their vulnerabilities are. If they live very close to the coast, like right on the coast, then certainly they have to pay attention to storms that may generate a storm surge,” said Robichaud. “If someone is highly dependent on having electricity, either for medical devices or even people who are on wells to have, if possible, some sort of backup power source.”
As many in Atlantic Canada saw with Fiona, fish harvesters can be some of the most drastically impacted by storms. Boats, fishing gear and wharves can take a serious beating from hurricanes and post-tropical storms.
Given that the track of storms can vary by hundreds of kilometres even 24 hours before they make landfall, anyone within the possible path of a hurricane should do all they can to minimize damages, whether that means pulling up and relocating traps or relocating vessels further inland.
“From some of that damage that I saw [from Fiona], especially in Newfoundland, even areas that did have breakwaters sustained some level of damage,” said Robichaud. “In terms of the fishing gear and the fishing vessels, short of relocating, I’m not sure that there’s a lot that can be done.”
As storms travel north towards Atlantic Canada and speed up, Robichaud also warned those in coastal areas to be aware of trapped fetches, where the area in which the waves are being produced is in harmony with the forward motion of the storm, which allows waves to build to heights not seen in southern latitudes.
“If you have an accelerating post-tropical storm approaching Atlantic Canada, you could have larger waves in a weaker storm than you would have in a category 5 hurricane in the Caribbean,” said Robichaud. “That is one thing that is good to know about these storms; the potential for these huge waves.”
Knowing the track of the storm and how it affects wind direction is also a useful piece of knowledge to have, according to the CHC. For example, if a storm is going east of one’s location, the winds of the storm will likely be going offshore. As a result, the storm surge from the winds will be far less significant.
“If the winds are onshore, then it’s a different ball game altogether. Then you’re probably going to get the worst of what that storm has to offer,” said Robichaud.
Two competing factors that Robichaud mentioned in the 2023 hurricane season are the presence of El Niño, where conditions in the Pacific Ocean can create fewer storms on the Atlantic side of Canada. On the other hand, unprecedented ocean temperatures in the Atlantic can have the opposite effect on the creation of storms.
“With that in mind, knowing there’s a lot of uncertainty in this year because of these two extreme competing factors, there’s no year more than this year to remember that it only takes that one storm to make it a bad year,” said Robichaud.
