Tornadoes Part 1: Tornado terminology, destructive power and myths


In West Texas the season of spring brings warmer temperatures and the long awaited hint of green to the winter-frozen, brown, cracked grass of the native area. But spring also brings the potential threat of tornadoes. With that in mind, members of the 17th Civil Engineer Squadron base readiness flight provide readers with information about tornadoes and what people can do to prepare themselves better during the tornado season.

"Tornado season in Texas generally begins in March, and subsides in July. The season peaks in this area in either May or June," said Wayne Click, 17 CE readiness flight chief.

"In order to prepare properly for the tornado season, a person must first familiarize themselves with some important terms concerning tornado season and understand the destructive power tornadoes can cause," he continued.

A tornado is defined as a rapidly rotating column of air extending from a cumulonimbus cloud with a circulation that reaches the ground.

"A tornado's path is narrow. This usually results in the damage of a tornado not being as severe like that of less violent, but larger storms," said Airman 1st Class Mark Nicholas, 17 CE readiness journeyman.

"A funnel cloud is a rapidly rotating column of air extending from a cumulonimbus cloud with a circulation that does not reach the ground. Once a funnel cloud reaches the ground it is then called a tornado," added Airman Nicholas.

"It is very important that people understand the difference between a Tornado Watch and a Tornado Warning," said Airman 1st Class David Le Beau, 17 CE readiness journeyman.

"A Tornado Watch basically means that weather conditions are right for a tornado to form, while a Tornado Warning means a tornado has been spotted usually by meteorologists using a radar system," Airman Le Beau added.

A scale that measures the size and strength of a tornado by its speed and destructive force classifies tornadoes into 6 categories, F-0 through F-5.

"This scale is similar in scale used for classifying a hurricane," said Airman Le Beau.

An F-0 tornado has a wind of 40-72 miles per hour. Some examples of this tornado's destructive force is chimney damage and broken tree branches.

An F-1 tornado has a wind of 73-112 miles per hour and can push a mobile home of its foundation and overturn it.

As the speed of a tornado and its destruction becomes more severe the category number gets higher.

"A tornado that falls into this category can have winds ranging from 265-319 mile per hour. Some examples of the destructive force of an F-5 are homes being lifted off their foundations and vehicles thrown as far as 100 meters or approximately 328 feet. That's about the size of a football field," said Airman Nicholas.

"Another thing people must do in order to prepare properly for this tornado season, aside from understanding certain tornado terms and the power of their destruction, is to stop believing in tornado myths," Mr. Click commented.

Below is a list of myths vs. facts regarding tornadoes provided for this article by the 17 CES Readiness Flight.


MYTH: Areas near rivers, lakes and mountains are safe from tornadoes.
FACT: No place is safe from tornadoes. In the late 1980's, a tornado swept through Yellowstone National Park leaving a path of destruction up and down a 10,000-ft. mountain.

MYTH: The low pressure with a tornado causes buildings to "explode" as the tornado passes overhead.
FACT: Violent winds and debris slamming into buildings cause most structural damage.

MYTH: Windows should be opened before a tornado approaches to equalize pressure and minimize damage.
FACT: Opening windows allows damaging wind to enter the structure. Leave the windows alone; instead, immediately go to a safe place.

This is part one of a two part series on tornadoes. Next week's publication will include information on what a person can do to stay safe in different situations and scenarios when a tornado threatens where you are.