Make some noise if you're a fan of snow!

[Squeaks squeaks]

Yeah!

We love to be outside when it snows.

We like to go sledding, make a snow fort, or even just take a walk!

But there are some times when it's definitely not a good idea to go out in the snow!

And one of those times is during a blizzard.

A blizzard is a kind of big snowstorm.

But it's a special one!

Blizzards start in the same way that some other powerful storms start: when two big

areas of air meet.

One of these big areas of air is colder, and the other is warmer.

To make a blizzard, the warm air gets pushed up so it's on top of the cold air.

Warm air on top of cold air makes conditions just right for lots of wind and water to come

together.

[Squeaks Squeaks]

That's true, Squeaks, blizzards don't usually have rain.

They have snow!

But remember what snow is made of?

[Squeaks squeaks]

It's frozen water.

Since the air that's on the bottom of the storm and closer to the ground is cold, the

water can freeze into snow.

Scientists say that for a snowstorm to be considered an official blizzard, three things

have to happen.

First, to be a blizzard, a snowstorm has to have a lot of wind.

And the wind has to blow pretty hard!

Winds in a blizzard have to blow at least 55 kilometers an hour — as fast as a car

driving down the street!

That makes it strong enough to blow around things that are outside, like lawn furniture

or garbage cans.

Second, the visibility in a blizzard has to be pretty low.

Visibility is just how far you can see.

When things like fog, snow, clouds, or rain get in the way, you can't see as far, so

we'd say the visibility goes down.

For example, on a clear sunny day, you might be able to see as far as the mountains in

the distance, which is pretty far!

[Squeaks squeaks]

Right, as long as there's nothing in the way, like trees or buildings.

But in a blizzard, visibility goes way down.

You might only be able to see two blocks down the street, or even less!

You can't see very far in a blizzard because of the snow that's falling from the sky

and being blown around by all that wind.

In some really strong blizzards, there might be no visibility — meaning you wouldn't

be able to see much of anything at all, even if it's only a few meters or feet away!

Sometimes when there's no visibility like that people will call it a “whiteout.”

That means the blowing snow makes it pretty difficult, if not impossible to see anything

but the color white!

Now, the third thing that separates blizzards from ordinary snowstorms is time.

To be a blizzard, a snowstorm has to last three hours—or longer.

So you can see why blizzards are some serious storms!

Have you noticed that there's one thing we haven't talked about when it comes to

what makes a blizzard a blizzard?

[Squeaks squeaks]

Oh, you know what, Squeaks, that's not what I was thinking of, but you're right: we

didn't talk about how cold a blizzard is.

Well, blizzards usually are very cold, but they don't have to be a certain amount of

cold to be called a blizzard.

But we also didn't talk about how much snow a blizzard has to have!

That's because blizzards don't have to have a lot of snow.

But they usually do have tons of it!

Lots of blizzards leave behind so much snow that it's taller than you, and some leave

behind even more — the snow can even be taller than me!

There are some places where big areas of warm and cold air meet pretty often during the

winter, so they get blizzards all the time.

For example, there are lots of blizzards right in the middle of the United States and Canada

because cold, dry air comes down from the North Pole and meets the warm, wet air coming

up from the water near Mexico.

Places like the Northeastern US, parts of the UK, Romania, Iran, and China can also

get some pretty big blizzards!

We just had a blizzard where we live a few days ago.

But since it's not snowing at all right now, I think it's the perfect time for us

to go outside and build a snowman!

C'mon, Squeaks, let's get bundled up!

Thanks for joining us!

If you want to keep learning and having fun with Squeaks and me, hit the subscribe button,

and we'll see you next time here at the Fort!

♪Outro♪