Using rain and snow measurements since 1950 and computer simulations for future climate, scientists calculated that for every degree Fahrenheit the world warms, extreme rainfall at higher elevation increases by 8.3% , according to a study in Wednesday'sHeavy rain in mountains causes a lot more problems than big snow, including flooding, landslides and erosion, scientists said. And the rain isn't conveniently stored away like snowpack that can recharge reservoirs in spring and summer.
The study looked at only the heaviest rains each year over six decades in the Northern Hemisphere, finding that as altitude rose, so did the turbocharging of rain. The biggest increase in rains were noticed at about 10,000 feet . That includes much of the American West, where Ombadi said “it’s very pronounced,” as well as parts of the Appalachian Mountains. Another big hotspot in Asia is the Himalayas, Tian Shan and Hindu Kush mountains, with the Alps also affected.
The study makes sense and “the implications are serious,” said UCLA climate hydrologist Park Williams, who wasn’t part of the research. Scientists expect more precipitation with warmer temperatures, but heavy snow’s flooding impact is lessened because it takes time to melt and it’s easier to monitor snowpack to see what’s happening, he said.
“This kind of extreme rainfall is going to make the floods worse. And then you’ve got to figure out where is that water going?” she said. “We have that situation right now in the Sierras with the Tulare Lake flooding and such a serious issue relating to that.”