The Central Sierra Nevada snowpack this year is larger than the previous four years combined, according to new data from NASA.
The Tuolumne River Basin alone contains 1.2 million acre-feet of snow. That's 21 times larger than what was recorded there in 2015, the driest year on record.
The space agency's Airborne Snow Observatory made the measurements back on April 1, prior to a series of storms.
Tom Painter is with the Jet Propulsion Laboratory in Pasadena. He says the high-tech data gives water managers a better tool than manual surveys.
"So, much of the uncertainty that they have experienced over the decades, in terms of runoff forecasting in the spring -- in terms of the total amount of water that's going to be coming out of the mountains -- has been largely due to that uncertainty of how much snow there is."
The Airpborne Snow Observatory now maps the snowpack of the entire Central Sierra Nevada including the San Joaquin, Tuolumne, and Kings River Basins.
Painter says he expects the entire Sierra to be mapped in the coming years.