When a tropical storm is approaching, its intensity or wind speed often gets the bulk of the attention. But as Tropical Storm Barry bore down on the Gulf Coast , it was the water that the storm would bring with it that had weather watchers worried.

The National Weather Service called for roughly 10 to 20 inches of rain to fall from late Thursday night through Saturday. The average rainfall for July in New Orleans, which is in the path of the storm, is just under six inches.

And Tropical Storm Barry, which may become a Category 1 hurricane before making landfall, will drop rain on already saturated land. On Wednesday, the region was hit by severe thunderstorms, which dropped as much as seven inches of rain according to preliminary National Weather Service data.

“Climate change is in general increasing the frequency and intensity of heavy rainfall storms,” said Andreas Prein, a project scientist with the National Center for Atmospheric Research.