Hurricanes can cause widespread damage, especially if the area hit isn't prone to them. One example is Hurricane Agnes in Pennsylvania in either 1972 or 1973. It occurred the week after the ground had been saturated from a storm that came from the West. Agnes did loops, going out to the Atlantic Ocean, then circling inland over Eastern and Central Pennsylvania. It was a 500-year flood in Pennsylvania, causing flooding in such diverse areas as the Scranton / Wilkes-Barre area, Harrisburg, and State College. Flooding rivers were the issue in the Scranton / Wilkes-Barre area and Harrisburg. The Susquehanna River along Front Street in Harrisburg had muddy water up to the second level of historic homes and buildings. In State College, parts of which are built on limestone caverns, it was underground water that filled them. (No rivers in State College) Damage occurred to basement foundations (water rising inside the concrete blocks of the walls leading to crumbling) and pot holes. Like a two-foot-wide pot hole that is eight-feet deep. Iron bridges, some historic, became twisted metal, pulled off the stream and river banks. Normally quiet streams became raging rivers that overflowed their banks. Roads can be not only flooded but also torn up by water.
Also, while the weather service often gets the hurricane paths pretty close, they can't always predict where it will stall, or even where it will make landfall. People can be stranded if they aren't warned ahead of time, even those familiar with hurricanes. Like last year's Category 5 that hit the West Coast of Florida, then crossed across the state. Even a storm that is a tropical storm just below the level of a hurricane can cause extensive wind and water damage if it batters the area for several days.
Superman could help with rescues and getting supplies into affected areas. And also finding hidden dangers, like underground flooding or buildings that are at risk for collapse by using his Xray vision. He could use superspeed to put up temporary shelters for any kind of disaster. It might be possible for him to reduce the intensity or even divert the path of a storm, although I can't explain how that might happen realistically.
