California is about to begin the “big melt” — the thawing of trillions of gallons of frozen water, currently sitting atop the Sierra Nevada mountains and about to make its way down into the Central Valley floodplain.
As the San Francisco Chronicle warns, this year’s swollen rivers “are going to run much higher, faster, colder and for longer than they normally would, posing risks to the hordes of summer lovers who raft, kayak, swim and fish them.”
PG&E launches its first airboat crew on the re-emerging Tulare Lake. The goal is to scout the area, disconnect impacted, and soon to be impacted customers, while removing equipment before it pollutes incoming snow melt. More tonight at 5 and 6. @KSEE24 @CBS47 pic.twitter.com/MMFgzfKbcS
— Ben Morris (@BenMorrisNews) April 20, 2023
As the Fresno Bee notes:
As temperatures warm up over the coming days across the central San Joaquin Valley, weather experts are predicting that a record snowpack in the southern Sierra Nevada will see an accelerated pace of melting, potentially adding to flooding woes on the Valley floor.
“The Big Melt is now officially arriving this weekend,” said Daniel Swain, a climate scientist at UCLA who has been monitoring the snow accumulation and snowmelt flood potential in California’s mountain ranges. “Flows on many rivers draining the central/southern Sierra will double or triple (with locally greater increases) as temperatures rise.
“Some rivers will exceed flood stage, and Tulare Basin flooding will worsen,” Swain said in a social media post Thursday.
The Los Angeles Times notes that predicted cooler temperatures in May could at least slow the thaw and limit the damage, or give local authorities and residents more time to prepare.
The winter of 2022-23 was one of the rainiest and snowiest in recent decades, with over a dozen “atmospheric rivers” pummeling the state, defying predictions of a third consecutive dry winter and bringing relief from a crushing drought.
Ski resorts plan to stay open through midsummer in many places, and residents and tourists both are basking spectacular spring blooms and waterfall hikes. But there are also concerns about how intensive flooding could affect the local agricultural economy and global food supplies and prices.
STRATFORD, CA: the last barrier separating Tulare Lake and town @ 3.5 miles.
📍 Video starts where the Tulare Lake Canal meets 19th & Manteca and down to Nevada. West to East portion extends along Nevada Ave from 19th to 20 1/2 Ave to where it meets the Kings River -South Fork pic.twitter.com/nhq2uUGUQS
— Martín Chávez (@ChavezMartinJr) April 16, 2023
Worries of flooding are added to by frustration that the state has failed to build new infrastructure to store the water for future dry seasons.
California towns recovering from destructive winter storms are preparing for more flooding when record snow starts melting and “rushing down like a diesel train” https://t.co/1SyQTGT6B4
— The Wall Street Journal (@WSJ) April 15, 2023
California’s ‘big melt’ has begun and could bring perilous flooding with it https://t.co/hPyR9AjTGj
— The Guardian (@guardian) April 17, 2023