Thursday May 19, 2022
The Conversation —
Much of the western U.S. has been in the grip of an unrelenting drought since early 2020. The dryness has coincided with record-breaking wildfires, intense and long-lasting heat waves, low stream flows and dwindling water supplies in reservoirs that millions of people across the region rely on.
Heading into summer, the outlook is pretty grim. The National Weather Service’s latest seasonal outlook, issued May 19, 2022, described drought persisting across most of the West and parts of the Great Plains.
One driver of the Western drought has been persistent La Niña conditions in the tropical Pacific since the summer of 2020. During La Niña, cooler tropical Pacific waters help nudge the jet stream northward. That tends to bring fewer storms to the southern tier of the U.S. and produce pronounced drought impacts in the Southwest.
The other and perhaps more important part of the story is the the hotter and thirstier atmosphere, caused by a rapidly warming climate.