With no rain in the forecast for the rest of 2020 — thanks to a La Niña weather pattern pushing storms north of the state — the probability of California entering a multi-year drought is increasing.
A study last week predicts that massive, often-devastating “hundred-year storms” may occur three times as often and be 20% more severe in the U.S. due to climate change. The researchers, in a paper published in the American Geophysical Union journal Earth’s Future, found that if greenhouse gas emissions continue to increase at a rapid rate, the continental U.S. would likely see such mega-storms every 33 years.
The occurrence of historic rainfall events, like the ones that caused Hurricane Harvey in 2017 and California’s Great Flood of 1862, are likely to increase faster than lower-magnitude events, which already happen about every decade, according to UCLA climate scientist Daniel Swain.
Atmospheric rivers (ARs)—long, sinuous corridors of water vapor in motion in the lower half of Earth’s atmosphere—are a key aspect of California’s cool-season climate. ARs are in many cases pretty unremarkable when they’re out over the open ocean, visible on satellite as a narrow ribbon of cloudiness and (usually) light precipitation. But when these moisture plumes attach themselves to wintertime low pressure systems and make landfall along the California coast, the consequences can be dramatic—prolonged heavy rain and mountain snow often result, along with sometimes powerful winds.
The Water News Network is San Diego County’s source for water news and information.
