High afternoon temperatures, well above normal for this time of year, are hitting Fresno and the central San Joaquin Valley, setting the stage for accelerated melting of the record Sierra Nevada snowpack and raising concerns about . Potential flooding in the Tulare Lake Basin.
The forecast for Fresno calls for temperatures to touch the 100-degree mark on Sunday, a significant increase from Friday’s 82 degrees.
“We believe we are going to be in a summer pattern for an extended period” for most of this week, informed of During a discussion about the National Weather Service forecast on Friday.
He aired friday one summer advice For the period from Saturday afternoon to Monday night, when forecasters urged people to stay out of the sun and stay in air-conditioned rooms, drink plenty of fluids, watch vulnerable family members and neighbors, and avoid children or pets Do not leave alone in vehicles.
David Spector, a meteorologist with the National Weather Service’s Hanford office, told The Fresno on Friday that as temperatures rise in the valley, “the mountains are warming more than the valley in terms of the amount of temperature added.” “We’re going to see an increase in snow especially early (this) week.”
Melting from massive amounts of snow in the southern Sierra Nevada on the eastern side of the valley can push rivers including the Kings, Caveah, and Tule beyond the capacity of their channels in the reaches above the dams at the bottom of the escarpment. , Spector said, “So we could see some flooding there.”
In the valley, however, “only the Kings River (Pine Flat) experiences flooding below the dam,” he said. Water released from Pine Flat Dam to make way for more snowmelt, and not diverted for groundwater recharge or agricultural use, flows into Tulare Lake, the county’s largest, normally dry lake. Thanks to a series of spring atmospheric river storms as well as snow.
UCLA climate scientist Daniel Swain said this week that cooler weather in the first week of May slowed the rate of snowfall somewhat after warmer weather in late April.
Snowfall in the Sierra Nevada Mountains
“The snow is still melting at a fairly rapid rate, but less so than during the heat wave that broke some records in late April,” Swinney said in a vlog on Monday.
But this weekend, he said, “snow will intensify again with a significant rise in temperatures.”
“A large portion of that water that was stored as snow in the Sierra is still there. It hasn’t melted yet,” Swain said. “It’s definitely melting faster and much of the snow at lower elevations is already gone. But of course, that’s not where most of the snow actually lived.”
“Most of the water ice was above 6,000 or 7,000 feet anyway, and that’s where the bulk of the ice resides,” he explained. “So that Central Valley flood risk, particularly the Tulare Lake and Tulare Basin flood risk, remains in place for weeks.”
“The best estimate is that in many places, the potential peak of snow won’t occur until late May and early June. So we still have a long way to go,” Swain said.
The potential for prolonged snowstorms and the continued excess flow of the Kings River into Tulare Lake has prompted officials to raise the level of the 14.5-mile levee that protects the city of Corcoran from a resurfaced lake. The State of California Has Provided Over $17 Million to Mobilize the Cross Creek Flood Control District four legs The levee—which has been compromised over the years by subsidence caused by over-pumping of the water table in the area—is 192 feet to 188 feet from its most recent height above sea level.
Gov. Gavin Newsom said early last week that it was the third time in decades that state or federal officials have taken action to raise the Corcoran Levee because of subsidence. Newsom and his administration officials saw firsthand the flooding of Lake Tulare that threatens Corcoran and two state prisons when they visited the area on April 25.
“Raising the Corcoran Levee provides greater certainty that we will not need to evacuate critical facilities and ensures public safety,” Newsom said Thursday. “However, the state and federal government cannot continue to intervene to increase this levy. I look forward to a conversation about what (Kings County) is going to do differently so that we don’t put ourselves in this position again.” Don’t get it.”