Friday, January 13, 2017

ATMOSPHERIC RIVER

This week the usually calm waters of Lake Natoma under the Rainbow Bridge are a boil.
In Northern California we have been riding the "atmospheric river" since last weekend. For boaters,  it's a Class 5 like waterfall that has swelled the state's rivers, flooded neighborhoods and vineyards, all while dumping snow and rain on the Sierra Nevada Mountains and causing mudslides on hills scorched by summer's wildfires.

An atmospheric river is long and narrow bands of water vapor that form over an ocean and flow through the sky. Massive quantities of Pacific Ocean water
from as far away as Hawaii have pummeled California with series of storms like a long blast from a fire hose. 
Courtesy of Heavenly Mountain via Facebook

Blizzard conditions forced road closures to many of Lake Tahoe's ski resorts that had to shut down and dig-out after being buried in snow. Nine feet fell in over three days at Kirkwood Mountain Resort in California making it the snowiest January in 45 years. Most of the ski resorts it looks like will try to open at least some terrain this weekend.

The Yuba River rose again to a little over 85 feet in Marysville California, while the South Fork of the American River are creating “once-in-a-decade”conditions on the American River for expert kayakers like Dylan Nichols. “We don’t have the option to run it this high maybe but once in a decade," Nichols told ABC10, "So it’s special for us local paddlers to be able to come out and take advantage of it,” Nichols and other expert kayakers paddled on the river from Chili Bar Park in Placerville California to where the water pours into Folsom Reservoir. He estimated the flow at 20,000 cubic feet per second, compared to a normal pace of anywhere from 1,500 to 3,000 cubic feet per second.

South Yuba River at Highway 49. Photo by Rich Shipley via Facebook
“It’s extremely unusual conditions,” professional kayaker Isidro Soberanes told ABC10, “It gives me the opportunity to experience a river I know really well at extremely high, high levels. Basically, I’m expecting to paddle some of the biggest rapids I’ve paddled in California.”

To see their trip down the South Fork, check out this link.  http://www.abc10.com/news/local/american-rivers-once-in-a-decade-conditions-draw-thrill-seeking-kayakers/385347076

Folsom Lake continues to rise with the week's rains, as water managers releasing even more water downstream.  Early this week the lake's water level stood at 422 feet elevation rising 13.5 feet higher than what it was 5 hours earlier. As the lake becoming fuller, the U.S. Bureau of Reclamation opened five floodgates at Folsom Dam and 18 gates at Nimbus Dam releasing the water downstream.

Due to releases and rain, the usual peaceful waters of Lake Natoma under Folsom's Rainbow Bridge became a violent torrent at the entrance to the lake. While downstream large sections of the American River Parkway and several popular Sacramento County parks were closed earlier this week after days of rainfall and heavy releases from reservoirs flooded recreation areas around the region.

The Jim Jones footbridge, one parkway’s biggest popular attractions for boaters, fishermen and summer time rafters at the Sunrise Recreation Area, remains underwater this week as the American River gushes over it. Meanwhile, much of the western half of the parkway, Discovery Park to about Watt Avenue, also will remain inaccessible for the time being due to flood waters.

While most atmospheric river events are weak. But the powerful ones like the one that just targeted California this week, can transport an amount of water vapor equal to 15 times the average flow of water that flows out of the Mississippi River's mouth, according to NOAA's Earth System Research Laboratory. This drenching is good news that might help bring a dramatic turnaround for the state's water supply after more than five years of drought.