Coastal Processes FAQ - What is it about Delaware's location along the Atlantic coast that makes it an unlikely landing point for hurricanes?

It's a rather complicated issue and there are many factors that influence the landfall location and intensity of tropical storms.

There are several factors that influence the strength and landfall location of a tropical storm or hurricane. These storms derive their power and strength from warm ocean waters (80 degrees Fahrenheit or greater water temperatures), and it's not until late summer/early fall that the ocean water temperatures off of Delmarva are high enough to support tropical storms. The Gulf Stream typically meanders up along our coast in September and October, making these months the most likely for strong tropical storms in the mid-Atlantic vicinity.

When tropical storms make landfall at a location to our south, the storm loses strength as it leaves its power source (warm ocean) and travels over land. However, significant wind velocities can occur well inland of the landfall location, and torrential rainfall can cause damaging floods in inland areas. Tornadoes are also a significant threat to inland areas after a tropical storm makes landfall.

I'm not a meteorologist, but I'll try to give you a general explanation about possible impacts on the tracks of hurricanes in the mid-Atlantic region. However, I'll warn you in advance that I'm not a weather expert!! The location and strength of adjacent weather systems have significant impacts on the track of a tropical storm. As these storms form in the tropical and subtropical latitudes of the Atlantic, they tend to move toward the west-northwest. This motion often brings the hurricane into the vicinity of the U.S. East Coast. Depending on the location of adjacent steering currents and weather patterns, these storms may generally either move into the Gulf of Mexico, up along the East Coast of the United States, or re-curve back out to sea. Quite often the pattern of the jet stream over the mid-Atlantic precludes direct landfall of a hurricane.

The trough associated with the jet stream may be strong enough to turn the tropical storm back out to sea. Similarly, the location of a “stationary” Bermuda high over the central Atlantic can steer tropical systems to the south. Additionally, the general pattern of weather system movement across the continental mid-Atlantic region is from west to east. Thus, any weather system moving across the continent, through the mid-Atlantic region, would likely have a westerly direction that would also work to "steer" tropical storms away from our coast.