We’re about to see a rare and record-setting may heat wave
It may still be spring, but baking summer heat is about to hit the famously comfortable Pacific Northwest and western Canada. Starting this weekend, the heat wave will send temperatures soaring 20 to 25 degrees Fahrenheit above average in some spots and potentially break records.
[...]
The new heat wave is also yet another reminder that summers are getting progressively hotter and arriving earlier as humans continue to release planet-warming emissions into the atmosphere.
[...]
The current meteorologic setup is very similar to the one that caused the infamous 2021 heat dome over this area, says Daniel Swain, a climate scientist at the University of California, Los Angeles, and the National Center for Atmospheric Research. Though the current ridge is occurring earlier and is centered farther north, it is still “a huge blob of essentially unprecedented atmospheric high pressure and temperatures for this time of year,” Swain says. This heat wave will have lower absolute temperatures in part because the event will happen a month earlier than the 2021 heat dome. The background temperatures are still somewhat cooler.
[...]
Though no specific study of the role of climate change in the upcoming event yet exists, it is clear that summers everywhere are heating up. Any heat wave that happens now can be expected to be warmer than it would have been in decades past. Summer is also increasingly expanding its reach while winter’s realm is simultaneously shrinking: A 2021 study found that over the entire Northern Hemisphere, meteorologic summer increased from 78 days in 1952 to 95 days by 2011. And the Pacific Northwest has seen clear trends in hotter summers. The average summer temperature in both Portland and Seattle is now about three degrees F warmer than it was in 1970, according to an analysis of climate records by Climate Central, a nonprofit climate research organization. The region is experiencing more days above 90 degrees—which is the threshold for extreme heat in that mild climate—and will expect to see those days coming steadily earlier in the season, O’Neill says. “What would once be considered a nice warm spring day can now rise above that 90-degree mark,” he adds.