(Intro)

Sabrina: Hi guys, welcome back.

(Sounds of thunder)

Today we're going to talk about-

(Sounds of thunder)

Sorry about that. Today we're going to talk about-

(Even more sounds of thunder)

Are you finished, thunder? Thank you. Thunder is pretty excited, because today's episode is all about it. Well, to be more specific, today's episode is all about severe weather.

But before things get all snowy, windy and rainy in here, let's bundle up and ask ourselves the big question: What exactly is severe weather and how is it different from regular weather?

We know that weather is a condition of the air, or the atmosphere on our planet. Severe weather is the same thing only... more extreme. EXTREME! But what does that mean? How do you know when weather is severe, or extreme, and when it isn't?

Well, severe weather is any dangerous act of nature fueled by changes in the atmosphere, that puts people, animals, or buildings at risk. Some light rain probably wouldn't count as severe weather, but a thunder storm with heavy rain and lightning, would.

Tornadoes, blizzards, hurricanes, floods and droughts are other forms of severe weather that can be dangerous to humans. But the more you know about these weather events the less scary they seem.

Let's start with tornadoes. A tornado is a fast-spinning column of air that stretches all the way from a thunderstorm cloud in the sky down to the Earth's surface. With wind speeds of up to over 300 kilometers an hour, tornadoes have the power to pick up and destroy everything in their path.

While not quite as windy as a tornado, blizzards are storms with blowing or falling snow, high winds, and cold temperatures.

Hurricanes, or typhoons, are storms with high winds and heavy rain that start as tropical storms that form over warm ocean waters, and bring lots of water with them.

Speaking of lots of water, let's talk flooding. Floods happen when too much rain forces streams, rivers and lakes to overflow, sending lots and lots of water where it doesn't belong. Like, your backyard.

A drought is sort of the opposite, think: a LOT less water, or no water at all. Droughts happen when an area doesn't receive enough rainfall, drying up rivers and lakes, killing trees and ruining crops.

All of those forms of severe weather have a big impact on the biosphere and the geosphere. How so? Let's find out. I'll conjure up some different types of severe weather, to see exactly how shakeups in the atmosphere can impact the biosphere and the geosphere.

Severe weather can be dangerous for people, obviously, but beyond affecting humans in the biosphere severe weather can also affect plants and animals, too.

Take a drought, after very long spells without enough rain, this nice mountain pond will become smaller, and maybe even dry up entirely. That means less habitat for the animals that live in the water like ducks and beavers. But it also means less plants life around because plants need water, too. And fewer plants mean less food for animals like deer and elk, that feast on them.

But what about the opposite problem? What about too much water in the form of heavy rain? Really strong thunderstorms can sometimes bring lightning and high winds that can damage trees, maybe breaking off some  of their limbs, uprooting them or even setting them on fire.

This is bad new, not only for the tree, but also for everything that lives in it. And finally, even the ground. As solid as it might seem, can be reshaped by severe weather.

Strong, recurrent flood waters act like powerful rivers and can actually wear down rocky formations, like mountains, over time. And sometimes big flows of rainwater can cause a slope or hillside to collapse, in an event called a mudslide.

The atmosphere interacts strongly with the other spheres of the environment, particularly when it's cooking up severe weather. It can even move things in the biosphere and reshape the geosphere.

So, now you know to tell if weather is severe or not. Ask yourself: Does it put life or property at risk? Does it have a major impact on the biosphere and the geosphere?

If the answer is yes, you're not dealing with normal weather patterns. Severe weather might be less common, but it has a much bigger impact on the world around you.

Anything to add, thunder?

(Silence)

I think that means we're done.

(Outro)