… Increased temperatures earlier in the year followed by other weather-related phenomena are causing much of the western United States to experience what scientists are calling “snow-eater” heat waves. A new study, published Wednesday in the journal Science Advances, analyzes the weather events using a method developed to identify the heat waves. Snow-eater heat waves are pretty much like they sound — abrupt snowmelt triggered by rain-on-snow and followed by several days of unseasonably high temperatures. … The authors noted that in the spring and early summer in the West, heat waves occur regularly. But they have nearly doubled in frequency and intensity since the mid-1990’s. And with those extreme temperatures comes increased snowmelt, which in turn can cause severe floods.