In the midst of this balmy, October weather, I sneaked a look at the weather a year ago. I saw an archived item about a local storm report — talking about snow in the Sierra Nevada. There were reports of heavy snow in the mountains of Fresno, Tulare and Madera counties.
Earlier in the month last year, there was an item about record heat. It was a good reminder of how quickly things can change in October.
No one has complained to me about temperatures in the 80s during the day and 50s at night. Air quality has been pretty good, too.
But if the nice weather continues into November, people will begin to get nervous about a third consecutive dry winter in Central California.
Two Fresno State professors say climate change will make the San Joaquin River’s annual runoff show up earlier — as much as six weeks earlier in the next century.
And one other thing:There will be a “significant decrease in annual stream flow,” said geology professor C. John Suen, who co-authored a study on the upper San Joaquin. Suen’s co-author was associate hydrology professor Zhi Wang.
The study, published in Hydrology Research, is more confirmation of findings in previous climate change studies, and it is not a pretty picture.
As water engineers and researchers have been saying for years, California’s reservoirs are built built to capture a gradual runoff from melting snow. More than half the state’s summer water supply is frozen in the snowpack each year.
If the state see more rainfall and earlier snow runoff, there could be big problems protecting communities and farms from floods.
In the San Joaquin Valley, the shift could be damaging for the multibillion-dollar economic base of agriculture.
This is about the place where the discussion turns to building larger reservoirs — such as Temperance Flat on the San Joaquin — or changing the way water and land are used. I’ll leave those issues to commenters here.
But Suen and Wang give us more reason to have the conversation.
It’s balmy in the San Joaquin Valley, but it’s still winter above 8,000 feet in the Sierra. Yosemite National Park on Monday will begin to assess the snow covering high country Tioga Road in preparation for plowing.
Each spring, the reopening of this road is anxiously awaited by businesses on both sides of the mountain, as well as many thousands of tourists.
In many years, it is open by Memorial Day, but not always. The earliest the road has opened in the last few decades has been April 29 in 1988, which was a drought year in California.
Will the road be open before that date? Nobody knows, says park spokeswoman Kari Cobb. She says crews on snowmobiles will take a couple of days to assess avalanche danger and snow conditions. Then park leaders will decide when the plowing begins.
By all accounts, it was a dry winter in the Sierra, but some places had more snow than others. The watershed for Yosemite’s two main rivers — the Tuolumne and the Merced — got a little more than half the usual snowfall. But the snowpack above 8,000 feet is 70% of average.
“There’s a lot of interest in the reopening,” Cobb said. “We will get updates on our web site as often as possible.”
The California Department of Transportation has cleared the road above the east-side community of Lee Vining all the way to the Tioga Pass entrance station, she said.