It’s too early to tell whether April snow in Portland is linked to climate change, scientists say

This week’s rare snowstorm could be an indication of climate change, but climate scientists say it’s too early to tell, as global warming trends make this event unlikely to be related.

According to data from National Weather Service, snow has been recorded in Portland at most six times during April, according to data back to 1872.

Oregon’s state climatologist Larry O’Neill said these late-season snowstorms have gotten less frequent as the climate gets warmer, but Monday’s snowfall should not be considered an extreme event, despite Portland temperatures reaching into the mid 70s last week.

The snowstorm was “typical weather variability and not any sign of climate change,” O’Neill said. “I think the real story here is that we used to get snow more often in April in Portland and now we don’t.”

The snowstorm in Southwest Washington, Western Oregon, and Southwest Washington A minimum of one inch of snowTo the Portland metro area. Portland International Airport, which is located in the National Weather ServiceIt began keeping records in 1940 and recorded the first snowfall and sticking during April 1940. The snowfall reached as high as 125 feet in the Portland metro area and Southwest Washington. 11 inches in some places.

But data from the National Weather Service’s previous downtown Portland officeThe data shows that there have been at least six instances where snowfall occurred in April over the past 100 year.

On April 1, 1936 in Portland, just over 5inches of snow was recorded. On April 7, 1933, a little over an inch of snow was also measured. In 1901, 1895, and 1903 there were also three cases where a tenth inch of snow was recorded in April.

O’Neill, who directs the Oregon Climate Service and works as an associate professor in Oregon State University’s College of Earth, Ocean and Atmospheric Sciences, said Monday’s snowstorm was not unprecedented but it was unusual in part because lowland snow is becoming less frequent as the climate is warming.

“Some people are saying, ‘Oh, extreme events happen more often under a changing climate.’ And some extreme events it is true, but this, I wouldn’t categorize as an extreme event, and it’s definitely not unprecedented,” he said.

O’Neill said lowland snow is typical during “La Niña,” a weather pattern that occurs in the Pacific Ocean that creates and shifts cooler temperatures up north during the winter while the south experiences warmer drought-like conditions. Lowland snow conditions could also be spotty as some areas will see snow that doesn’t stick.

Historically, O’Neill said, if the weather station did not get any snow, and other parts of the city or region did, it would not get recorded as a snow day since it did not occur where the National Weather Service has its official equipment.

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Climatologists in Oregon and Washington said the additional precipitation from this week’s storm Drought conditions can be improved, but not eliminatedAll across the Northwest

Paul Loikith, an associate professor of geography at Portland State University, said that he believes the snowstorm doesn’t have a strong link to climate change because spring weather has warmed over 80 years.

“It’s kind of in the opposite direction of the way the statistics are going as far as warming temperatures,” he said. “Aprils are warming in Portland. We’re seeing in general less extreme cold over time, and that’s projected to continue.”

Loikith said springtime is getting warmer and summer is the region’s fastest warming season, but warming is seen across every month of the year. Based on the trends and temperatures derived from current knowledge about how climate change is affecting this region, he said that it was unlikely that this snowstorm could be attributed to climate changes.

Loikith stated that there is no definitive answer until proper analysis has been done. Attributing the snowstorm to climate change could require running two weather models comparing the likelihood of this event occurring in a pre-industrial climate versus today’s climate.

“Weather is capable of a wide range of extremes, even in the absence of human activity,” Loikith said.

Loikith said a perfect example of an extreme weather event occurring because of climate change was last June’s heat dome event, as it aligns with warming trends in the region. Climate change can also cause wildfires, which are extreme weather events that occur due to rising temperatures.

“Those impacts we’ve already felt,” he said. “We can measure it. It’s clearly connected.”