Storm’s End
Just as many factors contribute to the birth of a hurricane or tropical storm, there are many reasons why a hurricane begins to decay. Wind shear can tear the hurricane apart. Moving over cooler water or into drier areas can lead to weakening as well. Landfall typically shuts off the main moisture source, and the surface circulation can be reduced by friction when it passes over land.
However, once a storm makes landfall, the danger isn't over. As the system moves inland, impacts from the storm including heavy rainfall, inland and river flooding, tornadoes, and high winds often continue to pose a significant threat. In fact, although storm surge poses the primary coastal threat from hurricanes, inland (or freshwater) flooding accounts for a substantial portion of the deaths from tropical cyclones.
Note too that a weakening hurricane or tropical storm can reintensify if it moves back over warm water or interacts with mid–latitude frontal systems. For example, Hurricane Ike in 2008 re–intensified as an extratropical low (that is, one that has lost its tropical characteristics) over the Ohio Valley a day after moving through Texas. The reinvigorated storm produced wind gusts to hurricane force in parts of Kentucky and Ohio, and its remnants caused approximately $4.4 billion in damages and killed at least 28 people.
Something to Think About
Why don't hurricanes typically hit the West Coast of the U.S.?
Tracks for all North Atlantic (since 1859) and Eastern North Pacific (since 1949) hurricanes
The larger atmospheric flow in which tropical and subtropical cyclones form generally travels in a west-northwest direction. That flow can easily bring hurricanes toward the East Coast, but it generally carries them away from the West Coast. Also, the waters of the Gulf Stream along the East Coast are quite warm (over 80°F/27°C) in comparison to those along the West Coast, which rarely get above 75°F (24°C). Remember that hurricanes need warm water to both develop and maintain their intensity.