Researchers measured how much water was stored in a river basin months ahead of the spring flood season.
"Just like a bucket can only hold so much water, the same concept applies to river basins," said lead study author JT Reager, an Earth scientist at the University of California, Irvine.
Reager and colleagues looked back in time using satellite data, and measured how much water was soaking the ground before the 2011 Missouri River floods, 'Live Science' reported.
Their statistical model strongly predicted this major flood event five months in advance.
Researchers said with less reliability, the prediction could be extended to 11 months in advance.
"This gives the background on what's on the ground before the rain even gets there," Reager said.
Reager's new method could help forecasters prepare reliable flood warnings several months earlier.
"It would be amazing if this could have a positive effect and potentially save lives," he said.
Researchers used NASA's twin GRACE satellites to diagnose a region's flood potential. As the satellites circle the Earth, changes in gravity slightly perturb their orbit.
These tugs are proportional to changes in mass, such as a buildup of water and snow.
The team looked at all potential water sources, including snow, surface water, soil moisture and groundwater, the report said.
"This gives us a more accurate interpretation of what's happening on the ground," Reager said.
The research was published in the journal Nature Geoscience.