0
Even in the precipitation-heavy Pacific Northwest, more frequent heatwaves are threatening a key source of water supply. A Washington State University study that intended to look at snow melting under a single, extreme event, the 2021 ‘heat dome,’ instead revealed an alarming, longer-term rising trend of successive heatwaves melting snowpack earlier in the year. From temperature records spanning from 1940 to 2021, springtime heatwaves in the region have doubled in frequency, intensity or both since the mid-1990s. The findings have implications for many areas worldwide that are dependent on snow-capped mountains to provide summer water since heatwaves have been on the rise globally.