Name: Tornadoes 101 | National Geographic
Uploaded: 2022-08-26T17:10:44.000Z
Duration: 5 min 32 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

gently coursing through a solitary existence,

but slowly, their gentility turns to rage.

They grow larger and larger, hurling and twisting,

and desperately reaching down from the sky,

Tornadoes are powerful spinning columns of air

that stretch from the ground to the clouds.

are extremely violent and cause immense destruction.

Tornadoes occur on six of the seven continents.

The country with the most tornadoes based on land size

is the United Kingdom with an average of about

But the country with the greatest overall

is the United States with over 1,000 reported annually.

are classified as either supercell tornadoes,

the most powerful class of thunderstorms,

is the presence of both high and low pressure air

Air particles from the area of high pressure

from the high pressure area to the low pressure area,

and in different directions and altitudes

they turn into an upright spinning vortex.

the circumstances are slightly different.

Violent supercell storms draw warm low-pressure air

leaving behind cool high-pressure air near the ground.

the two levels of air pressure into balance

The wind increases and starts to blow in a cyclical fashion,

creating a pipe of wind that rolls along the ground.

In both cases, an upward current of wind called an updraft

provides the final ingredient for creating a tornado.

an updraft lifts the rolling pipe of wind upward

Then it pulls condensation from the skies

As soon as the vortices, supercell or non-supercell,

they are officially classified as tornadoes.

All tornadoes are rated based on a system called

classifies tornadoes from a rating of EF0 to EF5.

The rating is based on a number of factors,

and the Doppler radar estimates of its wind speeds.

with the wind speeds between 65 to 85 miles per hour.

with the wind speeds exceeding 200 miles per hour.

occurred in Oklahoma City, Oklahoma in 1999.

the EF5 tornado had wind speeds of over 300 miles per hour.

It resulted in 36 fatalities, injured nearly 600,

measures are being taken to protect communities.

Meteorologists closely monitor storm fronts

In doing so, they help mitigate damages to neighborhoods

even in the face of one of nature's most formidable.

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Tornadoes 101 | National Geographic

intense

stretch

slightly

ingredient