Take another look at the passage:
Day after day, thunderclouds rolled in during the early afternoon. Making Madison's grass thrive from all of the water. Her neighbors, however, prayed for a sunny afternoon so that Madison could finally mow the jungle that was the front yard.
You chose the first part, Day after day, thunderclouds rolled in during the early afternoon. This part has a main clause: thunderclouds is the subject; rolled is the verb. A fragment will not have a main clause.