Here's how this week's heat wave will differ from June's historic heat dome

On Monday afternoon, Environment Canada issued a special weather statement warning of a heat wave that’s expected to hit British Columbia later this week.

The weather event will bring a strengthening ridge of high pressure, with temperatures reaching the low 30s in parts of Metro Vancouver and the Fraser Valley.

However, this heat wave will differ from the historic one that took place earlier this summer.

• See also: 
  • Environment Canada issues heat wave alert for Metro Vancouver this week
  • Hot, hot, hot: Vancouver forecast calls for seven days of sun, highs of 31°C
  • What the heck is the “heat dome” bringing record temperatures to Canada? 

According to Environment Canada, the highest temperatures are expected to take place between Thursday and Saturday. Fortunately, the heat wave looks to be short-lived.

“It’s not as long as the one we experienced in June and probably not quite as hot either,” Jennifer Hay, Environment Canada meteorologist, tells Daily Hive.

Hay explains that a heat dome, which is what occurred in June, is “much more fixed in place.” A high-pressure system circulates within a dome and continues to cycle with little ability to escape.

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

“It was a real blocking pattern, it just kept reinforcing itself with hot air coming from the US,” she explains. “We weren’t getting much relief from the ocean at that time.”

“That was a more historic event and also because it happened so early in the season, we really got record-breaking temperatures out of it. This time it is expected to be hot, and everyone should take precautions, but it doesn’t look record-breaking like the last one.”

A ridge of high pressure typically occurs in the summer when there are clear skies and subsiding air. As air eases down towards the surface, it compresses when it encounters areas of higher, higher pressure as it draws nearer. As that air gets compressed, it warms as well.

While this week’s heat wave is coming from a ridge of high pressure, it will likely break down faster and isn’t fixed in place.

Thursday to Saturday are expected to bring highs of 31°C to 32°C inland but fall to the low to mid 20s by Sunday and Monday.

Following the historic deadly heat wave earlier this summer, the public is urged to take precautions by staying cool and hydrated. Being attentive to symptoms of heat illness, including swelling, rash, nausea, vomiting, dizziness, tiredness, muscle cramps, heavy sweating, and cold, pale skin, is recommended.

The risks for heat illness are greatest for young children, older adults, pregnant women, people with chronic illnesses, and people working or exercising outdoors.

A total of 808 deaths were reported in BC between June 25 and July 1, 2021, with the vast majority attributed to heat-related causes. For context, the number of deaths reported in the same period in the province last year was 232. During this period, temperatures consecutively broke all-time records, reaching as high as the low 40s.

With files from Amir Ali and Kenneth Chan