Which phenomenon causes heavy rainfall specifically in late spring in Mississippi?

The phenomenon that causes heavy rainfall specifically in late spring in Mississippi is tropical storms developing in the Gulf. During this time of year, conditions are often favorable for the development of storms in the warm waters of the Gulf of Mexico. As the water temperature rises in late spring, it provides energy that can fuel tropical storms and hurricanes. When these storms approach the Gulf Coast, they can bring significant rainfall to Mississippi due to their moisture-laden winds. This heavy precipitation is often associated with the tropical storm's outer bands or the systems that may develop from them.

In contrast, tornadoes tend to be more localized and are not a primary source of widespread heavy rainfall over longer periods. Winter storms occur in the colder months and are not typically associated with late spring weather patterns. High pressure fronts are generally associated with stable weather and can inhibit precipitation rather than cause it. Therefore, the development of tropical storms in the Gulf is the key factor for late spring heavy rainfall in Mississippi.