What the heck is the "heat dome" bringing record temperatures to Canada?

Jun 28 2021, 9:22 pm

The term “heat dome” has been circulating the web a lot during this intense heat wave. While this is a relatively new addition to the Vancouver vocabulary, it’s something that many US cities have dealt with for years.

So, what exactly is a heat dome?

If you were to visualize a heat dome, it acts exactly as it sounds.

heat dome


Essentially, a high-pressure system circulates within a dome and continues to cycle with no ability to escape. It’s almost like a convection oven, but instead of roasting veggies, it’s roasting people.

Vancouver forecast

Vancouver forecast/Environment Canada

Other weather agencies have compared it to being like a lid on a pot.

When looking at what’s happening on the west coast, trapped heat is building up and creating a dome that is increasing Vancouver’s temperatures drastically.

With no place to escape, overnight temperatures will remain high in the province, moving well into the early hours of the morning with little to no relief.

How does a heat dome form?

While opinions range on social media following this heat wave, climate change is a real driving force behind extreme weather.

The main culprit in the formation of a heat dome is warming ocean temperatures.

According to an article from the National Oceanic and Atmospheric Administration (NOAA), western Pacific waters are heating up faster than eastern Pacific waters.

“If one thinks of the Pacific as a very large pool, the western Pacific’s temperatures have risen over the past few decades as compared to the eastern Pacific, creating a strong temperature gradient, or pressure differences that drive wind, across the entire ocean in winter,” says the NOAA.

“As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air and move it toward land, where it sinks, resulting in heat waves.”

When will it end?

The heat wave and heat dome will persist until the high-pressure system breaks down. This could be accompanied by severe thunderstorms as the hot and cool air clash.

According to Environment Canada, there currently isn’t any precipitation in the forecast for the next week, but this could be subject to change.

Tuesday is expected to be the last of the extreme heat in Vancouver. While it will still be hot, it will not be near 45°C hot.

As the overall temperature of planet Earth continues to rise, the heat dome might not just be a one-off crazy summer phenomenon but could become a normal occurrence.

A major heat wave in 2018 that affected the west coast was also thanks to a heat dome.

Amir AliAmir Ali

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