B.C. warned to brace for ‘dangerous long-duration heatwave’

VANCOUVER (NEWS 1130) — British Columbians are being warned to expect a “dangerous long-duration heatwave” starting Friday and lasting until at least next Wednesday.

Daytime highs are forecast to be as high as 38 degrees and nighttime temperatures are not expected to dip below 21 degrees. The warning covers Metro Vancouver, the Sea to Sky, and most of Vancouver Island.

Vancouver Forecast: A series of potential record setters from Saturday to Monday & check out the lows! #Hot #HeatWarning @NEWS1130 @CityNewsVAN pic.twitter.com/1Iy4PO1zeP

— Michael Kuss (@Kusswx) June 24, 2021

Environment Canada warns the unseasonable temperatures will likely cause other weather-related problems. It says expected record highs will raise river levels due to glacier melt, increase the risk of wildfires as forests dry out, and boost the potential for illnesses linked to heat or air quality as the high-pressure lid traps stagnant air over much of B.C.

“Humidex values during this period will reach the high 30s to possibly the low 40s,” according to the advisory.

“An exceptionally strong ridge of high pressure will develop over British Columbia likely resulting in record-breaking temperatures. The duration of this heat wave is concerning as there is little relief at night with elevated overnight temperatures. This record-breaking heat event will increase the potential for heat-related illnesses.”

.@environmentca issues a "dangerous long duration heatwave," for BC. It will start Friday and last until at least Wednesday. "Daytime highs ranging from 29 to 38 degrees combined w/overnight lows of 18-21 degrees. Humidex values will reach the high 30's to possibly low 40's."

— Sonia Aslam (@SoniaSAslam) June 24, 2021

Dr. Emily Newhouse with Fraser Health says preventing heat-related illness can mean going to places with air conditioning, swimming or having a cold shower.

“We also want people to still stay hydrated well in advance of being thirsty. So even before they think they need to drink water, they should be drinking lots of water,” she says.

Signs of heat-related illness include:

• dizziness/fainting
• nausea/vomiting rapid breathing and heartbeat
• extreme thirst
• decreased urination with unusually dark urine

Air quality concerns

The soaring temperatures forecast for B.C. over the weekend, mean air quality on the Lower Mainland could become a concern.

Kyle Howe is an air quality analyst at Metro Vancouver. He explains what the regional district will be monitoring, and what could prompt an air quality advisory.

“This is certainly a situation where ground-level ozone becomes a concern when temperatures rise like this. Ground-level ozone is formed with a mixture of sunlight hot temperatures and regional emissions,” he says.

“Typically with ground level ozone, we see the peaks occurring in the late afternoon and early evening periods Metro Vancouver will consider issuing an advisory if we feel that air quality warrants it. It’s important for people to remember that ground-level ozone is different than the ozone that we see in the upper atmosphere, which is actually protecting us from the sun’s UV radiation. When it’s at ground level though it can be really damaging to people’s health.”

RELATED: B.C., Pacific Northwest set for record-breaking June heatwave

Howe notes updated information about air quality is available online.

“We haven’t really seen concentrations, increased too much over the last couple of days, but as we move into the hotter period we’ll certainly be watching the data that comes in and making decisions around that,” he says.

“When we decide to call advisory it’s meant to be protective of people’s health. So we’re looking at various metrics and thresholds to determine when that advisory should be issued.”

Anyone with underlying health or respiratory conditions is urged to take precautions.

“People can do a number of things to protect themselves during this time,” Howe says. “Take it easy, find a cool place and stay hydrated, and try not over-exert yourself.”

With files from Crystal Laderas and the Canadian Press