What is a bomb cyclone? Meteorologist explains incoming B.C. storm
The tremors of the storm have been blowing harsh gusts across Vancouver Island and Lower Mainland for the past week. B.C. weather reports have been quick to spread the news of the impending bomb cyclone to hit the area Tuesday evening.
The storm’s daunting classification may spark fear as unfamiliar terminology, so what do these storms entail?
Environment Canada meteorologist Armel Castellan explains in an interview with CHEK News that storms deemed as bomb cyclones are not a new form of weather patterns.
“It’s a terminology that we’ve been using for a couple decades. Sometimes, you hear it as a ‘weather bomb,'” said Castellan.
Also known as a bombogenesis, or bomb cyclone genesis, the weather event by definition is an explosive beginning of a cyclone according to Castellan.
“What it means is that the central pressure in a low-pressure system that’s coming into the Pacific region deepens extremely fast,” he explained.
These storms usually occur in the western North Atlantic due to the regular mixing of cold and warm air systems, he says.
If pressure drops within a certain threshold — 24 millibars or more within 24 hours — then a storm can be technically defined as a bomb cyclone. The first bomb cyclone to hit B.C. in 2024 is expected to see a 55 millibar drop.
What does this mean we can expect on Tuesday?The storm will be 500 kilometers off the Island’s west coast, according to The Weather Network meteorologist Tyler Hamilton in a previous interview with CHEK News.
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So far, winds in Greater Victoria are expected to reach 90 km per hour and 100 km/h near Comox Valley and Tofino. Shorelines may see further damage due to large waves caused by the storm’s peak. The effects are expected to last up to 14 hours.
How common are bomb cyclones?This weather event is not predicted to be the highest on record in recent history. Another bomb cyclone hit B.C. in 2021, breaking the previous storm record from 1977, The Weather Network says.
The most recent previous bomb cyclone was last year in September 2023.
“It has occurred in the past and will continue to occur. Not necessarily every year will we see a bomb cyclone over the waters just adjacent to B.C., but every once in a while, we’ll see several of them in a given storm cycle,” says Castellan.
A 2021 study from Northern Illinois University led by Robert Fritzen found that, on average, there are 18 bomb cyclones a year across North America. Although the storm will be intense, bomb cyclones are not overly uncommon.
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With files from CHEK’s Kendall Hanson and Ethan Morneau
