Upcoming storm could melt massive snowpack, officials warn of potential flooding

Officials expect another storm to hit California, reaching the Sacramento region and Sierra late Thursday. The storm, which is predicted to be a warmer front, could melt some of the much-needed snowpack that was brought by recent storms. 

This comes after a survey last week found that statewide snowpack levels were almost double the average for this time of year. Experts are concerned a warmer storm could make snow melt prematurely and lead to flooding. 

Environment

California’s snowpack sees big boost after recent storms

Andrew Schwartz, lead scientist at the UC Berkeley Central Sierra Snow Lab near Donner Summit, said the possibility of flooding became more evident over the last weekend, as the forecast became clearer. In general, he said forecasts become more accurate the closer they are to the date being analyzed. As of right now, he said people living in areas downstream from snowpack, where flooding is more likely, should be prepared for the possibility of an evacuation notice. 

“The biggest thing and best thing that you can do to prepare yourself is just keep an eye on what the forecast is and what watches or warnings are currently out there,” he said. “Maybe treat it like forest fire season. Have a go bag ready in case you do need to evacuate quickly, but hopefully it doesn't come to that.” 

But overall, experts say these last few weeks have improved drought conditions in the state. Jay Lund, co-director of the UC Davis Center for Watershed Sciences, said the upcoming storm might melt some snowpack, but he doesn’t expect it to erase the progress made by earlier storms. He said the precipitation brought on by these storms has given the state a leg up in combating drought conditions. 

“The problems that we could have now are not nearly as bad as the problems we could have had, for drought anyway, a few months ago,” he said. 

Lund said drought impacts vary throughout the state, so some areas might see more lingering effects than others. In general, he expects to see longer-term effects on groundwater supplies, forest health and on species like salmon, which take longer to recover after prolonged periods of drought. 

“They've been depleted for quite some time and over several droughts,” Lund said of native fish species. “They never seem to recover during the wet years as much as they decline during the dry years.” 

A 2022 study on the American River Basin found that in the future, warming temperatures due to climate change will melt snowpack earlier in the year. According to the study, runoff historically peaked in May, but it will likely begin to peak sometime in March by 2050 and in February by 2085. 

Ryan Ojakian, legislative and regulatory affairs manager for the Sacramento Regional Water Authority, said his agency helped conduct the study. In the future, he said California should rely more heavily on groundwater to capture runoff during wet years that would later aid residents during dry years. 

“You're going to have long protracted periods where you'll have drought conditions followed by short, intense wet periods,” he said. “I think it becomes abundantly clear that what the changes are and where our solutions are, all signs point to we have to enhance our management of groundwater.” 

The National Weather Service in Sacramento advised residents to prepare for gusty winds Thursday night into Friday.