Storm hitting Atlantic Canada 'very similar' to what struck B.C.: meteorologist

TORONTO -

Last week, a devastating storm swept across B.C. and caused massive amounts of flooding and evacuations — now, Atlantic Canada is facing a storm caused by the same type of atmospheric conditions.

“It's a very similar storm,” Bob Robichaud, a senior Environment Canada meteorologist based in Nova Scotia, told CTVNews.ca in a phone interview.

“It's the same type of atmospheric setup that would generate this type of rainfall.”

He explained that this type of extreme rainfall event, like the one in B.C., occurs when a “very concentrated plume of moisture in the atmosphere that streams up from the tropics” becomes part of a storm.

“If there's a storm and you get this stream of moisture coming up from the south, [it’ll be] very, very comparable to what they had on the West Coast there last week. And in fact, in some areas of Atlantic Canada, we're potentially looking at even more precipitation than what fell in B.C. last week.”

The highest amount of rainfall that fell on one location during the initial B.C. storm was in Hope, B.C., which received more than 250 millimetres from Nov. 13 to Nov. 15.

Some models by Environment Canada suggest that more than 300 mm could fall in some regions, with certain parts of Newfoundland predicted to potentially receive over 400 mm.

• Read more: Western N.L. facing multi-day deluge; up to 400 mm of rain could fall in parts of province

“That would be quite a bit more than what fell on B.C.,” Robichaud said. “Now, it's expected to fall over a very small area that's not very populated, but still, whenever you have that amount of rain anywhere, it's going to cause a problem.”

When huge amounts of rain fall on mountainous terrain, for instance, it runs off into valleys and can cause issues such as flooding.

“We're approaching 200 already here in Nova Scotia, in eastern Nova Scotia, as of just about 20 minutes ago,” Robichaud said.

Although the regions at risk in Atlantic Canada are less populated than B.C., there are still people at risk when fast moving water accumulates.

“We had some water rescues that needed to be done this afternoon in parts of Nova Scotia where the water came up so fast in a trailer park [that] the fire department had to go out in boats and rescue people,” Robichaud said.

The rain will continue through the night in Nova Scotia, he said, and will “affect Newfoundland all day tomorrow.

“It won't be really until Thursday before things start to really improve marginally across all the areas that are affected,” he said.

During the transition from summer to fall to winter, there is a huge variability in weather, Robichaud said.

“Certainly that's what we're seeing with two major rainfall events here within a week on opposite ends of the coast.”

But while no one weather event can be tracked specifically to climate change, it has been shown to exacerbate extreme weather events, which could provide an insight into how Canada has been struck with so much rainfall recently.

Robichaud said that researchers are trying to investigate how strong the link might be between these types of events and climate change, adding that a warmer atmosphere can contain more water and thus has the potential for more severe rainfall.

“It is consistent with climate change that we will be getting more of these, especially these heavier rainfall events,” he said.

The struggle is not over for B.C. — there is more rain in the forecast for the province, which is still struggling to rebuild after heavy rainfall washed out highways and flooded towns. One system heading their way is more minor, but a few days after that, a “more significant” system could strike the area again.

“They're getting some more storms here as we head into the latter part of November and entering early December,” Robichaud said.