Hi I’m Elliott. This is Mental Floss on YouTube. Today I’m going to talk about some
misconceptions about the weather.
Misconception #1: Lightning comes from the cloud down.
Lightning comes from both clouds and the ground. But, when we look at lightning, what we’re
seeing came from the ground. According to the National Severe Storms Laboratory, “A
typical cloud-to-ground flash lowers a path of negative electricity (that we cannot see)
towards the ground in a series of spurts. Objects on the ground generally have a positive
charge. Since opposites attract, an upward streamer is sent out from the object about
to be struck. When these two paths meet, a return stroke zips back up to the sky. It's
the return stroke that produces the visible flash, but it all happens so fast - in about
one-millionth of a second - so the human eye doesn't see the actual formation of the stroke.”
And now that you know how lightning works... Misconception #2: Lightning strikes the tallest
object. Most likely, it WILL strike the tallest object
nearby. Because lightning is coming from both the ground and the sky, it’s ideal to have
less distance between those two things, which is why buildings and towers get struck the
most. But, once the lightning coming from the sky gets closer to the ground, it’s
not able to make distinctions between objects and find the tallest one. It will be most
attracted to tallest objects, but might hit the ground, or even a person, instead.
Misconception #3: It can be too cold to snow. For it to snow, there’s no requirement that
it must be cold, but not too cold. The only necessity is water vapor in the air. But,
there probably will be LESS snow if it’s very cold because the air has less water vapor
in it. In Antarctica, snow has been recorded in temperatures as low as negative 70 degrees
Fahrenheit.
Misconception #4: A tsunami means a single, giant wave.
It’s worth mentioning that this is probably the definition you’ll see if you look up
“tsunami” in the dictionary. But, a tsunami is considered any sudden displacement of a
large amount of water. Sometimes that means a bunch of smaller waves rather than one huge
one. And those can be just as devastating.
Misconception #5: The Polar Vortex is new. Though we hear the term a lot in the news
lately, there’s nothing new about the polar vortex, ok. The phrase dates back to 1853
when it was published in the magazine Household Words. John Capper wrote an article about
weather patterns and named the currents around the north and south poles the “great polar
vortex.” We have a similar meaning for the term nowadays. It refers to the two cyclones
that rotate around Earth’s two poles. Every once in a while, the polar vortex may shift
and start affecting our weather, like it did in January 2014. Something similar happened
in the late 1970s.
Misconception #6: Freezing rain means the raindrops are frozen.
Actually, the reason it’s called “freezing rain” is because the drops freeze when they
hit a surface. Basically, they fall through a lot of warmer air before they reach the
really cold ground. This causes instantaneous freezing when a drop hits a surface -- like
the ground or a car. And this is different from sleet, which freezes as it falls through
the air.
Misconception #7: You can tell how far away a storm is by counting the seconds between
when you see lightning and hear thunder. This is technically true, but most people
have the details kind of wrong. People usually believe that the number of seconds between lightning
and thunder is the number of miles between you and the lightning. In fact, the lightning
is even closer than that. The seconds counted need to be divided by five, and THAT is the
actual distance. So, if you count ten seconds between lightning and thunder, the lightning
is a mere two miles away from you. Sleep tight!
Misconception #8: Tornadoes don’t go through mountains and cities.
It’s rare for one to hit a city, but it actually does happen. For example, a tornado hit Oklahoma
City in 1999. And a few years later, in 2007, one went through Atlanta, Georgia. It doesn’t
happen often because cities take up less space on land compared to rural areas, so statistically,
tornadoes are more likely to hit the country. As for mountains, tornadoes have been recorded
in peaks as high as 10,000 feet. They’ve been found in the Rocky Mountains, the Appalachian
Mountains, and plenty of other mountain ranges.
Misconception #9: You’re safe in a car during a tornado.
So people typically say this because cars can technically go faster than tornadoes,
so outrunning one is possible, if not horribly terrifying. But, if the tornado is strong,
it can potentially hurl a car through the air. So, experts suggest that you take shelter
in a house or basement instead of your car. In fact, the National Weather Service recommends
that if you’re near a tornado and can’t be home, you should abandon your car and take
shelter in a ditch or low area.
Which brings me to... Misconception #10: Use a highway overpass
as a storm shield. There have been some widely-publicized cases
of people taking cover from tornadoes and storms underneath highway overpasses and being
totally fine. But, these were the exception, not the rule. And, in fact, in some of these
cases, the news stories left out the fact that the tornadoes didn’t even directly
hit that area. Many people have died doing this. And meteorologists now believe that
it might be the most dangerous place to be during a tornado.
If you have a topic for an upcoming Misconceptions episode that you’d like to see, leave it
in comments. Thanks for watching Misconceptions on Mental Floss on YouTube. Which is made
with the help of all of these wonderful people. And I will see you next week! Goodbye!