Drought concerns are so last year. This year, floods are the far likelier catastrophe in Northern California as the Sierra Nevada snowpack — currently at 190 percent of its historical average and the largest snowpack since 1998, according to the Bay Area News Group — is expected to melt this week amid an incoming heatwave. Per the Associated Press, National Oceanic and Atmospheric Administration forecasters expect the Merced River in Yosemite National Park to flow a foot over its normal levels beginning Wednesday, and for levels to keep rising higher from there.
There are no immediate flood risks projected here in the Bay Area, and our weather forecast this week calls for fairly standard early-May temperatures in the 60s and 70s. But that means temperatures in the 80s for Sacramento and western slope of the Sierra Mountains, and flood risks in places near Modesto, Truckee, and areas more adjacent to the Sierras.
The California Department of Water Resources is wrapping up its final survey of the winter, and they’re more than a little concerned about the regions surrounding the Sierra Nevadas. “The thing we’re looking out for is primarily the southern Sierra, where we have full reservoirs and in some cases a huge snowpack,” surveyor Frank Gehrke told Bay Area New Group. “We want to make sure that we prudently manage that so we don’t cause any downstream issues.”
State Fish and Wildlife officials say the historic snowpack has caused dozens of Sierra Nevada bighorn sheep to perish, and has kept black bears hibernation a month longer than usual. They discourage hiking and backpacking in the Sierras this week.
Officials do not expect flooding the caliber of the near miss at the Oroville Dam in February that caused massive evacuations, but they do caution Northern California swimmers and fishermen that rivers will be running exceptionally fast and cold during the snowpack melt.