Why Is it Raining?
Basics on the topic Why Is it Raining?
Why is it raining? How does rain fall from the sky? Learn more about how it rains and the water cycle with Uma in this interactive video! Take a look afterwards for exercises and worksheets to learn more about the water cycle and why it rains.
Transcript Why Is it Raining?
Looks like Uma's flower garden is in desperate need of water! Huh, (...) was that a raindrop just now? It's not going to rain, is it? I guess Uma doesn't need to water after all! But she still wonders, "Why IS it raining"? To answer that, let's first look at how a cloud is formed. See all those drops of water? How do they get into the cloud? There is water in oceans, rivers, lakes or streams, but also in soil and plants. When the water is heated by the sun, ... it rises to through the air as water vapor. The higher it goes, the COLDER the air gets, which is why the water vapor cools down. This can create water, or cloud, droplets that gather around small dust particles. This process is called condensation. That's how clouds are formed from water droplets. Will rain fall from every cloud? No. The water droplets in this cloud are light. Look how they dance back and forth. Because they are so light, they can float in the air. But, if more and more drops come together, bigger drops are formed. I'm sure you can imagine that they can't float back and forth as easily now as they did before, right? When they become too heavy, they fall to the ground as raindrops, ... sometimes as drizzle or othertimes as heavy rain. Why is that? If the air is really cold at the top, the water droplets turn into ICE crystals. Only when they fall down, do they thaw which makes BIG raindrops. If the air at altitude is warmer, then the rain may fall to earth as a drizzle. You see, there are different types of rain, or precipitation. Precipitation is more than just rain. Can you guess what else it could be? It could be snow (...) or hail. If it is cold outside, or thirty-two degrees Fahrenheit or below, the water droplets in the clouds freeze and fall to earth as snow. With hail, it's a little different. The wind plays an important role. Hailstones first come out of the cloud as raindrops. But before the raindrops reach the ground, the wind pushes them back up into colder layers of air. There they freeze and fall down as hailstones. On their way back to the ground, they encounter water droplets that attach to it. In the process, they can be sent high into the air again ... and melt together with more ice grains. This process continues until the hailstones become too heavy and fall to the ground. Sometimes hailstones can get as BIG as golf balls! I'm sure you can guess that it's not exactly safe, right? I wonder if Uma needs to water her garden flowers at all? It doesn't look like it ... ... well, we can put the watering can to use with the indoor flowers then!
Why Is it Raining? exercise
-
What is condensation?
HintsHow do the drops of water get into the cloud?
Water from oceans, rivers, streams, soil, and plants is heated by the sun.
The water vapor cools down as it gets higher in the air. This can create water, or cloud, droplets that gather around small dust particles.
SolutionCondensation is the process in which the water heated by the sun rises through the air as water vapor.
-
How are clouds formed?
HintsFirst, the water in oceans, rivers, soil, and plants is heated by the sun.
Second, the heated water rises through the air as water vapor.
Finally, clouds are formed from the water droplets.
Solution1.The water in oceans, rivers, soil and plants is heated by the sun.
2.The heated water rises through the air as water vapor.
3.The water vapor cools down because of the colder air.
4.The water, or droplets, gather around small dust particles.
5.Then clouds are formed from the water droplets.
-
How are hailstones formed?
HintsHailstones start as raindrops.
Lastly, hailstones become too heavy and fall to the ground.
Solution- Hailstones first come out of the cloud as raindrops.
- Before the raindrops reach the ground, the wind pushes them back up into colder layers of air. There they freeze and fall down as hailstones.
- On their way back to the ground, they encounter water droplets that attach to it. In the process, they can be sent high into the air again and melt together with more ice grains.
- This process continues until the hailstones become too heavy and fall to the ground.
-
How are raindrops formed?
HintsLight water droplets float in the air.
Bigger drops form when more drops come together.
SolutionWhen the water droplets are light, they float in the air.
When more drops come together, bigger drops are formed.
When the drops become too heavy, they fall to the ground as rain drops.
-
What are the different kinds of precipitation?
HintsThere are 3 correct options.
This is one type of precipitation.
This is another type of precipitation.
SolutionPrecipitation occurs when warm air pushes water vapor high into the atmosphere. When the water vapor cools, it condenses into water droplets that can stay liquid or freeze.
All forms of precipitation start the same, but they end in different forms.
The main forms of precipitation are: rain, snow and hail.
-
Is it more likely to rain or snow?
HintsSnow falls when the temperature is below freezing.
Rain can begin as snow high in the clouds. The snowflakes become raindrops through the warmer air.
It often rains in spring.
SolutionIf the weather is very humid; the temperature is 34ºF; or it is May, it is more likely to rain.
If it is very cold outside; the temperature is 30ºF; or it is February, it is more likely to snow.
