Tara Reid recently said in an interview that a sharknado really could happen. Contrary to all you sharknado truthers making fun of Reid, I agree with her assessment. The real question is to figure out where a sharknado is most likely to occur. Let's take a look at the science.
What kind of storm do we need?
The first hurdle we approach is the battle between shark waterspout (sharkospout?) versus a sharknado. A waterspout forms when rising air begins to stretch out and rotate, creating a rotating column of air; the low pressure inside the column condenses the water vapor and creates a smooth, tall tornado-like structure. Waterspouts are different from tornadoes in that tornadoes require rotation from within a thunderstorm in order to develop.
When a tornado forms from a thunderstorm over water, it's still called a waterspout, but it's a tornadic waterspout. Regular ol' waterspouts don't usually have winds much stronger than 60 or 70 MPH in the most intense cases, so they're hardly enough to suck up a shiver of sharks. We would need a tornadic thunderstorm to move over shark-infested waters in order to see Tara Reid's vision come true.
This greatly narrows down where we can have a veritable sharknado.
Where are the sharks?
Where are shark-bearing tornadoes most likely?
We can determine this crucial piece of science-evidence by looking back at a post of mine from a few weeks ago titled "64 Years of Tornado Tracks Look Like a Jackson Pollock Painting." I still have all of the GIS data I used to make that map, so I isolated tornadoes rated EF-3 and stronger (136+ MPH) and took a look at where these intense tornadoes occurred close enough to the coast that they could theoretically move over water, scoop up a shiver of sharks, and land people.
Since a good number of classic tornado outbreaks involving supercell thunderstorms travel from southwest to northeast, we can rule out most of the Gulf Coast for sharknado activity. Similarly, EF-3 or stronger tornadoes in Florida are exceedingly rare (back in 1966 the state saw its only F4, with its path running a disputed 134 miles from Tampa to the Atlantic), so Florida is out, too.
This leaves us the east coast of the United States where a) a tornadic supercell can form and b) move over water and then move back over land. Let's take a closer look...
The one spot on the East Coast prone to intense tornado outbreaks like the ones we see in the Deep South or the Plains is eastern North Carolina. The eastern side of the Tar Heel State is an ideal location for intense tornadoes because, during tornado outbreaks, it experiences strong winds aloft coming in from the west as well as strong southerly winds at the surface coming in off the Atlantic.
This leaves us with the possible scenario of an intense tornadic supercell forming over land, moving out over one of the sounds on the west side of the Outer Banks, then making landfall somewhere on the Outer Banks as a sharknado.
The Most Likely Spot in the United States for a Sharknado Is...
The appropriately- and prophetically-named Kill Devil Hills, North Carolina. Based on the North Carolina coast's vulnerability to shark attacks, as well as Kill Devil Hills' location on the other side of Albemarle Sound from mainland North Carolina, the city is the most likely to be hit by a sharknado one day.
Sorry, Kill Devil Hillians.
[shark-shaped storm map via SPC, all other maps by the author]