Heat Dome, Pineapple Express, Water Jet: Extreme Weather Events, a New Normal in British Columbia

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Cyclone Bomb, Heat Dome, Pineapple Express – If it seems like you’ve heard of extreme weather events with weirder names lately, you’re not imagining it.

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Over the past year, the frequency of powerful storms and deadly heat waves wreaking havoc in British Columbia has popularized certain weather terms and names, some of which sound more catchy than others.

Faron Anslow, a climate scientist with the Pacific Climate Impacts Consortium in Victoria, says climate change is partly to blame for the language.

“Individual weather events in British Columbia have gotten more extreme, we’re seeing rising temperatures bring warmer summers and winters,” Anslow said. “The public is now paying much more attention to climate change and repeating the terms used to describe some of its effects.”

In June, an unprecedented heat wave was discovered that caused nearly 600 deaths from extremely high temperatures as a result of human-caused climate change, said Anslow, who was part of an international team of researchers studying the heat wave.

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More recently, a dramatic meteorological event called a “water jet” hit the ground like a tornado that accumulated damage and debris on part of the University of British Columbia campus on Sunday.

These names, which may seem new to the public, have been around for quite some time, Anslow said.

“Many of them have ties to meteorological science.”

Heat dome

A term coined this summer after a crest of extremely high pressure, or heat, built up over BC

The so-called “heat dome” was a strong ridge of high pressure that trapped hot air underneath it. Like a dome, it did not allow fresh air to enter. Instead, with each passing summer day, the sun warmed the region and triggered a scorching heat wave, Anslow said.

“We see high-pressure ridges that often create hot spells in British Columbia in July and August, but never before as extreme as last June.”

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Cyclone pump / weather pump

A rare “weather bomb” hundreds of miles off the coast of British Columbia in late October was caused by a rapidly deepening low-pressure system, Anslow said. This event was also called a “bomb cyclone.”

The term is in a process called bombogenesis, in which an area of ​​low pressure rapidly intensifies, causing a storm to become stronger and stronger, bringing wind and rain to dry land.

“They often form in the North Pacific in the fall and winter as cold air from Alaska mixes with warm air from the south, off Asia,” Anslow said.

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Pineapple Express / atmospheric river

No, not the Seth Rogen movie.

A “Pineapple Express” is an “atmospheric river” of moisture that runs from the tropical Pacific to the coast of British Columbia.

A narrow corridor of moisture enters a low-pressure center that spins the storm off the coast and draws water vapor in the form of heavy rain.

“It is known to cause large floods and, if temperatures are cold enough, it can cause massive amounts of snow,” Anslow said.

Waterspout

Tornadic waterspouts are tornadoes that form over water or move from land to water, Anslow said. They are associated with severe thunderstorms and are often accompanied by strong winds and seas, large hail, and frequent lightning.

“A tornado is a strong pulse of cold northern air that forms under a convection storm. A waterspout, since it was formed on the water, is full of dew. “

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Waterspouts typically dissipate quickly if they make landfall, Anslow said.

Polar vortex

Among the public, a polar vortex is treated as the opposite of a heat dome. It is commonly written in the media as an event in which a cold air mass descends from the Arctic and forms a dome that does not allow the exchange of air from its surroundings. The result is a cold snap.

“To scientists, the term means something completely different,” Anslow said.

In science, the term polar vortex refers to a large area of ​​cold air around the North Pole of the Earth.

The most recent polar vortex event in British Columbia was in February 2021, when winter weather settled over western Canada after hitting the central and eastern parts of the country in late January.

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