Local scientists at Scripps Institution of Oceanography are closely watching a storm system as it moves into Southern California.

Scientists are releasing weather balloons every three hours to study the storm system, classified as an atmospheric river.

“An atmospheric river is just a large amount of moisture that’s associated with the system,” said program analyst Brian Kawzenuk. “An atmospheric river is sort of what it sounds like: it’s a river in the atmosphere.”

The weather balloons will collect a plethora of data including temperature, wind speed, direction and more, allowing scientists to map out a vertical profile of the atmosphere as the system approaches.