'Bomb cyclone' developing off B.C. coast, potentially bringing hurricane-force winds

Wind at English Bay in Vancouver. (Shutterstock)

An Environment Canada meteorologist says a so-called "bomb cyclone" is expected to bring powerful winds to Vancouver Island and the British Columbia coast this week.

Brian Proctor says these systems are caused by a rapid drop in atmospheric pressure at the centre of a storm.

Environment Canada posted a special weather statement saying the "significant" storm will develop about 400 kilometres off the coast of Vancouver Island on Tuesday, bringing high winds and heavy rain to some coastal areas that afternoon.

The advisory says the weather system may cause downed trees, travel delays and power outages, adding that peak winds are expected for most areas Tuesday night, though the severe weather is likely to continue into Wednesday.

Proctor says the storm will likely have the most impact on the west side of Vancouver Island and the central coast.

Matt MacDonald, the lead forecaster for the BC Wildfire Service, says in a social media post that models show B.C. coastal inlets could see "hurricane force" winds of more than 118 km/h and there may be waves of up to nine metres off Washington and Oregon's coasts.

Proctor says he wouldn't be surprised to see those kinds of winds and waves on B.C.'s coast.

"That would be fairly typical for this kind of track," he said in an interview. "Where they are actually going to be is going to be dependent upon where the track of the low pressure centre is and how close to Vancouver Island it comes in before it starts hooking northwards."

BC Ferries says in a statement that it is "closely monitoring the weather situation" and is in contact with Environment Canada, but sailings are expected to proceed as scheduled.

"Safety is always our top priority," it said. "Our crews are trained to follow strict operational procedures in line with Transport Canada’s safety regulations, and we are prepared to respond to any changes in conditions."

A La Nina winter is expected for B.C., and Proctor said the creation of bomb cyclones are amplified under those conditions, when ocean temperatures are cooler than normal.

He said the province should brace for similar storms, though not of the same magnitude.

"We're really setting up for a fairly typical late fall, if I can put it that way, once we get past this big event of this bomb cyclone," he said.

The special weather statement comes after a lightning storm overnight and early Monday covered parts of Metro Vancouver in hail.

B.C. has been hit by a series of powerful fall storms, including an atmospheric river that caused flash flooding in Metro Vancouver in mid-October.

The Insurance Bureau of Canada said in a news release last week that last month's storms caused $110 million in insured damage claims, which prompted it to renew calls for the federal government to "fully fund" the National Flood Insurance Program.

It said insured losses related to severe weather in Canada now routinely exceed $3 billion annually and a new record has been set this year, reaching more than $7.7 billion.

This report by The Canadian Press was first published Nov. 18, 2024.