It's Raining Fish and Spiders (2 page)

What Is a Tornado?

Tornadoes are the most destructive force on the face of the Earth. In terms of “extreme weather,” tornadoes are the most awesome, devastating force when you consider how they are created, their various ways of destruction, and the surprising way in which they attack. No other weather phenomenon destroys more property or causes more fatalities than a tornado. Derived from the Spanish word
torna
, meaning “to turn,” a tornado is defined as an intense, rotating column of air extending from the base of a thunderstorm cloud to the ground. Tornadoes can strike at any time, appear from any direction, and have hit every state in the United States, including Alaska and Hawaii.

The swirling debris field of a tornado has been clocked to move as fast as nearly 300 miles per hour. Tornado winds have destroyed wind-measuring instruments, caused pine needles to penetrate bricks, driven straw into trees, and stripped pavement off roads. Tornadoes have caused the roofs of large buildings to be lifted from their frames. The building's walls then fall outward and the roof is dropped back onto the structure, crushing it.

National Oceanic and Atmospheric Administration/Department of Commerce; Photographer: Joey Ketcham

National Oceanic and Atmospheric Administration/Department of Commerce

Wood, bricks, pipes, steel, tin siding, cars, tanker trucks, train cars, and even livestock have all been swept up into the storm and carried for miles. There's even one story of the Worcester, Massachusetts, tornado of June 9, 1953, when mattress pieces were carried high into the thunderstorm, when they were coated with ice, before they fell into Boston Harbor.

Unfortunately, people are injured and sometimes killed by tornadoes. In isolated cases, people have been carried as far as a mile from their homes. However, thanks to improved weather forecasting, the use of Doppler radar, and better public awareness, the number of deaths due to tornadoes is fortunately going down.

Another interesting phenomenon of the tornado is its ability to pass over ponds, lakes, or swamps and literally suck up the contents of these bodies of water. At least fifty times a year there are reports of fish, frogs, tadpoles, snakes, eels, or snails dropping from the sky, often landing on unsuspecting people. The debris field is sometimes carried quite high up, into an area where the weather is sunny and nice. As the storm weakens and dissipates, the storm can no longer support the debris, and it will fall to the ground in an area where there is no sign of bad weather!

There have even been reports of frozen fish falling from the sky! In those cases, the tornado passed over a pond and picked up its contents, including the fish. The water and fish were lifted way up into the atmosphere, to a height where the air can be as cold as -90 degrees Fahrenheit (F)/-68 degrees Celsius (C). The fish became encased in ice balls, and then dropped from the sky. Once a fish went right through the windshield of an automobile! It was because of this extreme weather phenomena that I originally wanted to name this book
Did You Know That Fish Could Fly…and Other Acts of Cod
.

More tornadoes occur in the United States than in any other country on Earth. On average, nearly 1,000 tornadoes are reported each year. What actually causes a tornado to drop from a thunderstorm still remains unknown. Even when all the ingredients for a tornado are present, the storm may never form. This is a great mystery to the scientists and meteorologists who study tornadoes.

How Are Tornadoes Born?

To understand how a tornado works, we must first understand where it comes from. Tornadoes are born from thunderstorms. Thunderstorms form in unstable air when there is warm air at the ground and cold air aloft. Due to this temperature profile, most thunderstorms occur in spring and summer, rather than in fall and winter. In spring, the sun warms the air at ground level, which rises into the cold winter air that still remains high above in the atmosphere at that time of year. This mix of warm and cold can cause violent thunderstorms that create not only tornadoes, but also destructive straight-line winds, damaging hail, and extensive flooding from heavy rains. In fall, the air at ground level is also warmed, but it rises into the warm summer air that remains aloft, so thunderstorms, and tornadoes, form less often.

National Oceanic and Atmospheric Administration/Department of Commerce
Frank Picini

National Oceanic and Atmospheric Administration/Department of Commerce
Frank Picini

Frank Picini

The Life of a Thunderstorm

Updrafts—warm, humid air rises from the ground (
Towering Cumulus Stage
).

 

As the air cools to its dew point, it forms a cloud.

 

Ice crystals or water drops grow big enough to overcome the updraft, they begin falling, dragging down the air (
Mature Stage
).

 

The falling precipitation and air being dragged down form downdrafts.

 

Updrafts continue feeding warm, humid air into the storm. Existence of both updrafts and downdrafts make this the storm's most violent stage.

 

Downdrafts grow, choking off updrafts (
Dissipating Stage
); with its supply of humid air cut, the storm begins dying and rain tapers off.

What Are the Best Conditions for a Tornado?

Extreme thunderstorms, ones that create deadly tornadoes, have special ingredients. The most deadly and destructive tornadoes form from
super cells
—which are rotating thunderstorms with a well-defined radar circulation called a
mesocyclone
(which we will discuss later). This type of storm is rare and only occurs in the United States. Characteristics of tornado-producing storms include: