Heatwave May Have Contributed to Mount St. Helens Landslide, Poses Risk for Wildfires

Record-Breaking Heat, Thunderstorm, Rain and Smoke All in a Matter of Days


Someone must have given her a lame present last year, because Mother Nature certainly made her mighty presence known this Mother’s Day.

From Sunday to Monday in Southwest Washington, she dealt out record-breaking heat, thunder and lightning, rain, rainbows, enormous billowing clouds and a watercolor-esque sunset. 

At the National Weather Service’s Olympia monitor, the closest one to the Twin Cities, temperatures on Sunday reached 90 degrees. Meteorologist Maddie Kristell, who works for the weather service forecast office in Seattle, said it was the hottest May 14 on record.

The next highest May 14 occurred in 2018, when temperatures reached 88.

Evaluation is ongoing, but the Washington Department of Transportation, in a news release this week, said a “catastrophic” bridge- and road-destroying landslide on the road to Mount St. Helens may have been caused by the significant jump in heat.

With the snowpack melting at faster-than-usual rates, the department’s initial theory on the slide’s cause was that “oversaturated soils … (and) overfilled the channels of the slopes, causing debris to join high water, which built up and then broke free, rolling downstream (and) washing out the 85-foot bridge span and roadway.”

As for the thunder and lightning that followed on Monday evening, Kristell said this time of year is when residents can expect such storms with as much “vigor” as the one this week. During the transition to the warmer seasons, she said, storm patterns meeting heat can up the regularity of thunder. 

“In this case, the ingredients just lined up. It timed out pretty well … and unusually coincided with some significant heat,” Kristell said. “It looks like things are going to calm down a bit heading into the weekend and early week. … We should have some cooler marine air coming in.”

For the forecaster, it’s hard to say how the wild weather relates to climate change. However, Kristell said, with heavy storms off the Cascades bringing rainfall, the weather service is closely watching the burn scars of last summer’s significant wildfires. The Goat Rocks Fire burn scar, while not as concerning as the Bolt Creek Fire scar, she said, poses some risk to the Cowlitz River basin as it is so near the Cascades.

“That one we’re watching,” Kristell said.

Dr. Christi Chester Schroeder, who holds a doctorate in physical chemistry and focuses on the study of air quality said, “It’s no big secret that summers are getting longer, hotter and drier as a result of climate change.”

While Southwest Washington’s heatwave doesn’t pose an immediate threat for air quality, Chester Schroeder said, it can significantly dry out vegetation, leaving behind a “tinder box” for larger, and “more explosive” wildfires.

Wildfires are currently burning in Alberta, Canada, the Seattle weather service office reported on Wednesday, causing “well-lofted” smoke to cover Northern Washington. The weather service shared a satellite image of the smoke on Twitter at sunrise Wednesday, noting it was “easily spotted” from above. 

Chester Schroeder — who works for IQAir, a tech company that collects and distributes a large collection of real-time air quality data — said as these hot summers extend, people across the United States should be checking on their air quality, regardless of what’s happening in their own region.

“I would really love for everyone to consider the air quality just like you would consider the weather,” Chester Schroeder told The Chronicle on Wednesday, later adding, “air quality issues are not just a local issue. There is pollution happening all over the world and … the wind doesn’t stop at countries’ boundaries. Time goes on and climate change continues, these weather patterns that we’re seeing are going to continue to intensify. Having a general awareness … can have a huge impact on your health.”

Alberta’s wildfire smoke doesn’t, at this time, pose a risk to air quality in Washington, the weather service said. But, Chester Schroeder urged that people should not rely on their visual sense to check air quality.  

“The air might not ‘look’ bad,” she said. “It’s very easy to disregard the dangers posed by hazardous air because you can’t always rely on your physical sense.”