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Ep257: What causes Snow and Sleet? · Kidcast Daily

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  Spin the wheel, let's take a ride.
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  Sports and science bursting from inside a world of wonder open
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  wide. Come on kids, let's amplify kid
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  cats. Daily starts your day.
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  Fun and laughter come your way. Sports and trivia games galore.
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  Welcome to Kick Ass Daily, where we bring news, trivia, fun
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  facts, and more just for curious kids like you.
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  Today we're diving into the chilly world of winter weather
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  to answer a great question. What causes snow and sleet?
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  If you've ever watched big, fluffy snowflakes fall or seen
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  tiny ice pellets bouncing on the ground, you might have wondered
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  how these different kinds of wintry precipitation form.
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  Let's explore the science behind snow and sleet together, step by
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  step. First, let's start with the
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  basics. Both snow and sleet are types of
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  precipitation. Precipitation is any form of
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  water, liquid or solid, that falls from the sky to the
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  ground. Rain, hail, snow, and sleet are
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  all forms of precipitation, but today we'll focus on the two
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  that make winter so unique. To understand how snow and sleet
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  form, we need to talk about clouds and temperature.
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  Clouds are made-up of tiny water droplets or ice crystals.
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  The temperature, both high up in the sky and down near the ground
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  plays a big role in what kind of precipitation we get.
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  Let's start with snow. Snow forms high up in cold
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  clouds when the temperature is below freezing.
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  This means below 32°F or 0°C. In these cold conditions, water
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  vapor in the cloud changes directly into ice crystals,
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  skipping the liquid stage. These ice crystals stick
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  together and grow into snowflakes.
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  As snowflakes get heavier, they begin to fall toward the ground.
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  For snowflakes to reach the ground without melting, the air
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  between the cloud and the ground must stay below freezing.
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  If the air stays cold all the way down, the snowflakes will
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  stay frozen and you'll see snow falling.
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  This is what happens during a classic snowstorm, when the
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  temperature outside feels chilly and you wake up to a white,
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  snowy world. Here's a fun fact No2 snowflakes
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  are exactly alike. Each snowflake forms in a unique
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  pattern depending on the temperature and humidity in the
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  cloud. Some snowflakes are flat and
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  thin, while others are thick and fluffy.
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  Scientists have even captured photographs of more than a
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  billion different snowflakes, and each one has a unique
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  design. Now, let's talk about sleet.
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  Sleet looks different from snow. Instead of soft, fluffy flakes,
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  sleet falls as tiny, hard pellets of ice.
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  How does this happen? The answer is all about the
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  layers of air between the cloud and the ground.
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  Imagine you have a cloud full of snowflakes high up in the sky.
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  The snowflakes start to fall just like before.
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  But this time the air below the cloud isn't all the same
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  temperature. There might be a warm layer of
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  air somewhere between the cloud and the ground.
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  When snowflakes fall into this warm layer, they melt and become
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  raindrops. If those raindrops then fall
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  into a second cold layer of air close to the ground, they freeze
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  again, this time into tiny ice pellets.
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  That's sleet. This means that sleet needs a
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  very specific situation, a layer of warm air sandwiched between 2
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  cold layers. The warm air melts the snow, and
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  the cold air refreezes it before it hits the ground.
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  If the cold layer near the ground is thick enough, you'll
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  get sleet instead of rain or snow.
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  When you see sleet, you might notice it makes a tapping sound
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  as it hits the window or bounces on the sidewalk.
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  Let's pause for a trivia question.
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  Do you know which country holds the world record for the most
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  snowfall in one year? Think about it.
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  I'll give you a few seconds. The answer is Japan.
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  In the city of Sakayuansen, located on the island of Honshu,
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  over 1200 inches, about 100 feet of snow fell during the winter
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  of 1981 to 1982. Now let's get back to sleet.
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  You might wonder what's the difference between sleet and
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  hail. Both are made of ice, but hail
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  forms during thunderstorms, not just in the summertime.
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  Hailstones grow as they're tossed around by strong updrafts
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  inside thunderstorm clouds, collecting layers of ice until
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  they fall to the ground. Sleet, on the other hand, forms
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  only in winter weather, through the melting and refreezing
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  process we just talked about. Here's a yes or no question to
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  get you thinking. Can sleet ever form on a hot
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  summer day? What do you think?
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  The answer is no. Sleet needs cold air, especially
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  near the ground, so it only happens during colder months.
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  Let's take a closer look at temperatures and why they matter
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  so much. The freezing point of water is
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  32°F or 0°C. If the temperature is above this
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  point, precipitation usually falls as rain.
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  If it's below, it can fall as snow or sleet, depending on the
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  air layers. Meteorologists, those are
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  scientists who study the weather, use special instruments
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  like weather balloons to measure the temperature at different
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  heights in the sky. This helps them predict if a
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  winter storm will bring snow, sleet, or even freezing rain.
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  Speaking of freezing rain, you might wonder how that's
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  different from sleet. Freezing rain starts out the
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  same way as sleet. Snowflakes melt into raindrops
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  as they pass through a warm layer of air.
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  But if the cold layer near the ground is very thin, the
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  raindrops don't have enough time to freeze into pellets before
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  they land. Instead, they hit the ground as
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  liquid and freeze instantly, forming a slippery, icy coating.
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  That's freezing rain, and it's different from both snow and
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  sleet. Let's try another trivia
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  question. What is the largest snowflake
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  ever recorded? Take a guess.
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  The answer is that in 1887, a snowflake measuring 15 inches
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  across was reported in Montana, USA.
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  That's bigger than a dinner plate.
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  Now let's talk about how snow and sleet affect everyday life.
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  When it snows, people often go sledding, build snowmen or have
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  snowball fights. But snow can also make driving
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  difficult and cause schools to close.
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  Sleet can make roads and sidewalk slippery, so people
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  have to be extra careful walking or driving.
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  In some places, cities use salt or sand on the roads to help
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  meld ice and provide traction. Here's a yes or no question for
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  you. Do all clouds produce snow or
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  sleet in the winter? What do you think?
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  The answer is No. Only certain types of clouds,
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  usually thick Gray clouds called nimbostratus or cumulonimbus,
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  produce enough moisture and the right temperatures for snow or
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  sleet. Let's look at where snow and
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  sleet are most common. Snow falls in many parts of the
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  world, especially in regions with cold winters like Canada,
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  Russia, northern Europe, and the northern United States.
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  Some mountainous areas get a lot of snow because the higher you
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  go, the colder the air becomes. Sleet is most common in places
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  where the temperature often hovers around freezing, just
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  cold enough for snow, but sometimes warm enough for rain.
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  This is why places with changing winter temperatures, like the
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  central and eastern United States, can see a mix of snow,
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  sleet, and freezing rain. Here's another trivia question.
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  Which animal changes the color of its fur in the winter to
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  blend in with the snow? The answer is the Arctic fox.
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  Its fur turns white in the winter to help it hide from
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  predators and hunt for food. Before we finish, let's do a
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  quick recap of what we've learned today.
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  Snow forms when ice crystals and cold clouds stick together and
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  fall through cold air all the way to the ground as snowflakes.
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  Sleet forms when snowflakes melt into raindrops as they pass
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  through a warm layer of air, then refreeze into ice pellets
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  in a cold layer near the ground. The temperature of the air, both
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  high up and near the ground, decides whether we get snow,
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  sleet, or something else entirely.
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  And while snow and sleet can make winter fun, they also mean
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  we need to be careful on slippery roads and sidewalks.
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  Remember, next time you see snow falling or hear sleet tapping on
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  your window, you'll know exactly how it forms and why it looks
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  the way it does. Thanks for joining us on Kid
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  Cast Daily. Stay curious, keep asking
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  questions, and we'll see you next time for more fascinating
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  facts and fun learning. Grab your breakfast, feelings
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  fine adventures waiting. Don't be late.
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