Where Is Tornado Alley?

Where Is Tornado Alley?
  
Captain Robert Miller was the meteorologist (an expert on weather forecasting) on duty the evening of March 20, 1948, at Tinker Air Force Base in central Oklahoma. While he had alerted the base of approaching wind gusts of thirty-five miles per hour, he didn’t realize that the otherwise quiet evening he had predicted would soon be turned upside down when a tornado would rip through the base later that night.

The tornado (also sometimes called a “twister”) raced through the Oklahoma City countryside before striking Tinker at 10:22 p.m. The funnel battered buildings and destroyed fifty-four aircraft. Airplanes left outside of hangars were tossed around like toys. Tools and airplane parts became dangerous objects in the fierce wind. After crashing through the base, the tornado disappeared. In the blink of an eye, the storm had caused more than $10 million in damage. The next morning, soldiers surveyed the destruction with amazement. How could the tornado have struck without warning? Nothing like it had ever happened before at Tinker. The US Air Force couldn’t afford for it to happen again.

The following day, Major Ernest Fawbush and Captain Robert Miller were tasked with examining past storms and weather patterns in the area. It was up to them to help find a way for Tinker Air Force Base not to be caught off guard by another tornado.

This wasn’t an easy task. Fawbush and Miller didn’t have access to the computer technology of today. In the 1940s, people relied on hand-drawn weather maps, crude weather-balloon information, and other charts and graphs for their research.

For the next several days, Fawbush and Miller studied past tornado-producing storms in Oklahoma. They hoped to reveal a pattern to the weather statistics they had on file that would let them predict tornadoes. If they could predict storms, the men could provide advance warning to the military bases around the country.

Perhaps Fawbush and Miller could even expand their work to help warn towns and cities. The pair felt a personal responsibility to prevent destruction and save lives.

Tinker Air Force Base sits directly in what Fawbush and Miller would later come to call “Tornado Alley.” The term refers to a strip of land starting in Texas that stretches north through the states of Oklahoma, Kansas, Colorado, Nebraska, Iowa, and South Dakota. There are no official boundaries for Tornado Alley. The nickname simply refers to an approximately 500,000-square-mile area within the United States.

There are four elements at work in Tornado Alley that make it a perfect place for twisters to form. The upper atmosphere is home to a strong jet stream—the winds that form between pockets of warm and cold air. While cold, dry air blows down from Canada, warm, dry air travels north from Mexico. Those air masses soon meet the moist air drifting in from the Gulf of Mexico. Because Tornado Alley sits in a lowland region, there are few physical barriers—like mountains—to block or redirect the airflow. As these air masses collide over the entire area of Tornado Alley, they create the perfect recipe for sudden and dangerous storms.

After days of reviewing weather reports, Fawbush and Miller found the pattern they sought. Minutes before each tornado had touched down in the state of Oklahoma, the weather patterns
on the map appeared eerily similar. The two men felt confident they could predict a tornado, but they’d have to wait for another severe storm to put their theory to the test.

And they didn’t have to wait long.

Five days later, on March 25, Fawbush and Miller paid close attention to the weather as another storm brewed nearby. The men recognized the telltale weather patterns that they associated with the birth of a tornado. They had to act.

Fawbush and Miller begged their commanding general, Fred Borum, to issue a tornado forecast for Tinker Air Force Base. Borum resisted. He knew that if he issued the warning and a tornado didn’t touch down, soldiers wouldn’t take future warnings seriously.

The meteorologists were faced with a difficult choice: They could keep quiet and risk even more tornado damage, or they could push the general to issue the tornado warning in hopes of saving lives.

Fawbush and Miller knew exactly what they had to do.

Chapter 1
The History of Meteorology
  
It seems that for as long as humans have been around, they have been intrigued by the weather and how to predict it. Throughout history, many great minds have studied the weather, a practice which came to be known as meteorology.

The first known meteorologist (someone who studies the weather) is thought to have been the Greek philosopher Aristotle.

Aristotle took an interest in big concepts including philosophy and the weather. In 340 BC, he wrote a book titled Meteorologica. It contains one of the earliest explanations of Earth’s atmosphere (the layer of gases that surround planet Earth). However, that wasn’t Aristotle’s only major contribution. His theories that the Earth was round, that the moon orbited the planet, and that Earth consisted of four main elements—-earth, wind, fire, and air—-were widely accepted by astronomers of his time.

Even before Aristotle, the ancient Egyptians believed they could control the weather and often held rituals to summon rain. (These were not always successful.)

Many ancient cultures who lived hundreds of years after Aristotle, and didn’t have access to his writing, believed the weather was controlled by gods.

The Maya living in Central America looked to Chaac, their god of rain, thunder, and lightning. These early Mesoamerican people believed that Chaac carried a lightning ax, and when he struck the clouds, it created thunder and rain.

Between the years AD 300 and 900, the Maya developed their own systems of science, astronomy, architecture, timekeeping, and meteorology. They observed the skies and recorded what they saw over hundreds of years. As time went on, they recognized weather patterns and planetary movements. Soon, the Maya were predicting weather with greater accuracy.

As Aristotle’s Meteorologica was translated to more and more languages, it was used as the basis of meteorology right up to and through the seventeenth century. There were still several inventions coming that would help take weather prediction from a dream to a reality. The first of those important inventions was the barometer. A barometer is a scientific instrument used by meteorologists to measure the rise and fall of atmospheric pressure, which is air pressure within the atmosphere. This tool helps predict the weather by indicating if a storm is going toward or away from a town or city.

Evangelista Torricelli, an Italian physicist and mathematician, is often credited with inventing the barometer in 1643. Torricelli was also the first scientist to describe the cause of wind. The second invention to change meteorology forever was the thermometer, a tool for measuring variations in temperature.
 
Aristotle (384–-322 BC)

Aristotle was a philosopher who lived in ancient Greece. Throughout his life, he wrote about many topics including science, economics, politics, biology, and psychology.
In addition to laying the foundation for meteorology, Aristotle advanced science in many ways, including his early concepts of physics, his system for classifying living organisms, and his ideas on zoology (the study of animal behavior).
Aristotle even started a school in Athens, Greece, where he not only taught about science but helped his students to achieve happiness in their lives.
 
The thermometer was created in 1709 by Daniel Gabriel Fahrenheit. A Dutch scientist and inventor, Fahrenheit created a scale to measure fixed points of temperature. Two of those points included the temperature of the human body (98.6 degrees Fahrenheit) and the freezing point of water (32 degrees Fahrenheit). Fahrenheit, the unit of temperature measurement, was named after him.

Though Italian astronomer Galileo Galilei had created a water thermoscope in 1593, in 1714 Fahrenheit invented the version filled with mercury (a slippery, naturally occurring chemical element) that is widely used in the present day.

In addition to playing a role in the greater understanding of meteorology, Aristotle’s book Meteorologica contained some of the earliest writings about tornadoes.

Aristotle believed tornadoes started as spinning wind trapped inside of clouds, and as the wind escaped, it pulled the clouds along to form a funnel shape. Aristotle’s theory wasn’t quite right, but he didn’t have any of the tools to fully understand tornadoes at the time. And we are still learning about tornadoes, and how they form, today.

Chapter 2
How Tornadoes Form
 
Tornadoes are sneaky. They can form quickly and without warning. In fact, when a tornado first forms, it’s invisible. At their core, tornadoes are powerful spinning columns of wind and air. It’s only after they pick up dirt or other objects that we can see tornadoes with the naked eye.
The most common type of tornado begins as part of a supercell thunderstorm, a weather system with rotating winds. Supercells form when an updraft of warm and moist air shoots upward into the atmosphere. This sudden updraft creates a rotating area within the thunderstorm strong enough to trigger a tornado warning. The rotating mass of air is called a mesocyclone, and it’s the very beginning of most tornadoes.

A tornado forms when moist, warm winds collide with dry, cold winds. As these weather patterns come together, the warm air rises over the cold air and cools as it goes up into the sky. As the air falls back down, it begins to spin. Imagine a clothes dryer as it tumbles the laundry end over end. That’s exactly how a tornado begins. As the winds spin faster, a funnel shape forms in the air. When one end of the wind funnel touches the rotating mesocyclone, and the other end touches the ground, it’s officially declared a tornado.

Tornadoes may last only minutes, like the one that struck Tinker Air Force Base in 1948. But some last for hours. A twister’s strength and duration depend on the weather conditions inside and around the supercell thunderstorm that created it. Powerful supercells are not limited in the number of tornadoes they can produce. Some supercells are large weather systems that spawn multiple tornadoes over the course of minutes or hours.

When multiple tornadoes form from a single supercell, it’s known as a “tornado outbreak.” Such outbreaks are responsible for the worst tornado-­related destruction in history.

Tornadoes have touched down on every continent in the world except Antarctica. While tornadoes can form anywhere, they’re most common in the United States. On average, more than one thousand tornadoes touch down in the United States each year during tornado season.
Tornado Alley isn’t the only place a dangerous tornado can occur within the United States. There are three other geographical regions, also called “alleys,” that scientists and meteorologists keep a close eye on.

The least dangerous of all the alleys is Carolina Alley, which can be found in North and South Carolina. Carolina Alley produces an average of twenty to thirty tornadoes each year. Hoosier Alley includes parts of Kentucky, Illinois, Indiana, Ohio, and Michigan. This area is slightly more dangerous than Carolina Alley, experiencing one to two hundred tornadoes each year.

While Tornado Alley may have the scariest of names, it’s a stretch of land in the southeastern United States that earns the title of “most dangerous.” Covering eastern Texas, Louisiana, Arkansas, Mississippi, Missouri, Tennessee, Alabama, and Georgia, this southeastern strip averages hundreds of tornadoes every year. Tornado Alley is responsible for producing 30 percent of all significant twisters in the United States, the southeastern region produces the most destructive ones. Why is that? The southern states are close to the humid weather of the Gulf Coast (the part of the Gulf of Mexico that forms a coastline along four of these states) and the constant dry winds that blow in from the west.

These weather fronts—air masses of different temperature and density—smash together over the southeastern region, allowing tornadoes to form at any time of year.

Many areas of the United States cool off at night, but the persistent warmth and humidity of the southern states means that many tornadoes in the region strike at night when residents are asleep and unable to react.

It’s no secret that tornadoes can form anywhere; it’s why they form that continues to baffle meteorologists. It’s the same question that Fawbush and Miller wanted to answer in 1948.