As a hurricane or tropical storm approaches your location, its forward speed decreases from 20 kt to 10 kt. how might that affect rainfall? a. less flooding because rain will have more time to soak into the ground b. less total rainfall from a weakening system c. more total rainfall from a slower moving storm d. shorter period under the rainbands

The correct answer is c. More total rainfall from a slower moving storm.
When the the forward speed of the hurricanes and tropical storms slows down they tend to increase the rainfall. Because of the slow movement the storm can be for few days over a given region and produce rainfall without stopping, thus create major flooding, pilling up of the coastal water, and produce persistent strong winds even though they have decreased in their forward speed.