Throughout history, we've heard accounts of animals raining from the sky. Small fish rained down on a Canadian city in 1903; fish, frogs, and crayfish fell from the sky in Alabama in 1957; a tadpole downpour came down on Japan in 2009. But no account is more fantastically terrifying than that of the movie Sharknado, whose sequel, Sharknado 2: The Second One, releases today.
Met with positive reviews and quickly becoming a cult classic, the original made-for-television B movie owes its success to the brainless approach it takes to its absurd premise: tornadoes are scooping sharks out of the ocean and flinging them at hapless, delicious Los Angelites. But how absurd of a concept is it, really?
A tornado is a violently rotating column of air whose wind speeds can reach more than 300 miles per hour. If a tornado forms or crosses over a body of water, we call it a waterspout. While "fair weather" waterspouts are about as common and "harmless" as dust devils, tornadic waterspouts can be severe.
Many of us who were alive in the '90s are passingly familiar with tornado classifications, thanks to the movie Twister and its deadly F5 tornado - the deadliest rank on the Fujita scale. Today, we use an Enhanced Fujita scale, but the take-home message remains the same: an EF5 tornado - which occurs once every few years - is powerful enough to rip homes off their foundations and toss around large trucks.
Surely, something that powerful can send sharks flying at Los Angeles, right?
A great white shark typically ranges in weight from 1,500 to 2,500 pounds, while tornadoes have been known to toss trucks as heavy as 80,000 pounds. There have been reports of cows - which can weigh hundreds to a couple thousand pounds - being flung a full mile. But what's important to note is that trucks, cows, and houses are all located above ground, in the direct path of the tornado's powerful winds.
The inside of a tornado is a vortex, yes. The air pressure within the tornado is lower than the air pressure outside of the tornado, which causes the upward whirling of particles. But the much stronger force is the wind blowing laterally. Objects blown into the air by the winds may be carried upward temporarily by the vortex, but they are rapidly ejected by the tornado's winds and launched in a random direction.
"While the tornado is spinning air along the surface of the water, it's not necessarily like a vacuum where it's sucking up sharks or sucking up marine animals out of the depths of the ocean," said National Weather Service spokesman Christopher Vaccaro. "So odds are the sharks wouldn't even be close enough to be entrained in the circulation of the water spout in any way, let alone would they be lifted because they weigh so much."
When people see waterspouts, what they believe they are looking at is water getting sucked up from the ocean and into the air. In actuality, a waterspout consists primarily of air, and what water we do see is mostly condensation, just like with a land tornado. The low pressure zone inside the tornado causes water to condense from humidity; it does not suck up a swirling column of water. Intense waterspouts do cause the surface of the water to raise by a few feet due to the pressure differential, but a tornado isn't a sealed vacuum - the air pressure is only about 10% lower inside than outside.
What this means is that the core concept of Sharknado is, indeed, as absurd as it seems. If you were to encounter a tornado powerful enough to hurl objects as heavy as sharks, you should be much more afraid of the tornado itself.
But then how do we explain all the historical accounts of raining animals?
Attempts at scientific explanations have been put forth, but the phenomenon hasn't been observed and documented well enough for any strong consensus to form. Strong winds can blow around groups of small animals, but why wouldn't they go splat upon hitting the ground? Why does the rain consist of only a single species of animal? How many of these accounts actually consist of raining animals and how many are simply mistaken migratory patterns?
The terrifying reality of raining animals is that... we simply don't know. And what's more frightening than the unknown?