What is precipitation?
Summary
TLDRThis educational video script delves into the fascinating world of precipitation, exploring not just rain and drizzle, but also extreme weather events like hailstorms and blizzards. It explains the formation of clouds and precipitation through the condensation of water vapor and the processes of coalescence and aggregation. The script also covers how different weather fronts influence cloud types and precipitation, and it highlights the dynamic nature of hail formation within powerful cumulonimbus clouds. The video encourages viewers to consider the complex journey of raindrops from vapor to cloud droplets, and possibly even hail, before they reach the ground as rain.
Takeaways
- ☁️ Precipitation includes not only rain and drizzle but also extreme weather events like hailstorms and blizzards.
- 🌡️ Clouds form when water vapor in the atmosphere cools and condenses into droplets or ice crystals, depending on the temperature.
- 🌬️ Various processes can cool the air and lead to cloud formation, such as warm fronts, cold fronts, and surface heating.
- 🌦️ Weather fronts often result in cloudy skies, with rain, drizzle, or snow, especially during colder times of the year.
- 💧 Rain and drizzle differ primarily in droplet size, with drizzle consisting of very small droplets that can reduce visibility.
- ❄️ In colder climates, precipitation often begins as ice crystals that form when clouds develop in sub-freezing temperatures.
- 🌨️ The aggregation of ice crystals with supercooled water droplets leads to the formation of snowflakes.
- 🌧️ Rain in temperate climates typically starts as snow but melts before reaching the ground if the air below the cloud is above 2°C.
- ⛈️ Cumulonimbus clouds, driven by strong convection, can produce heavy rain and are characterized by an anvil shape indicating the presence of ice crystals.
- ⚡️ Hailstones form within these clouds through a process of freezing and melting as they are carried up and down by air currents, growing layers like an onion.
Q & A
What is precipitation and why is it not just about rain and drizzle?
-Precipitation includes all forms of water that fall from the atmosphere to the Earth's surface, not just rain and drizzle. It also encompasses extreme weather events like hailstorms and blizzards.
How are clouds formed and what role do they play in precipitation?
-Clouds form when water vapor in the atmosphere cools and condenses into droplets. They are the starting point for all precipitation as they provide the medium for water droplets or ice crystals to form and grow.
What causes the cooling process that leads to cloud formation?
-The cooling process can occur in various ways, such as air rising along a warm front, approaching a cold front, or being heated by the Earth's surface and then rising.
How does the difference in droplet size distinguish rain from drizzle?
-Rain and drizzle differ by the size of the droplets involved. Drizzle consists of very small droplets, half a millimeter or less in diameter, while rain involves larger droplets.
What is the process by which drizzle droplets become large enough to fall as rain?
-Drizzle droplets merge or coalesce until they become large enough to fall from the cloud under their own weight.
In what conditions does snow form and how does it relate to rain in colder climates?
-Snow forms when clouds develop in or move into an area of the atmosphere below freezing. In colder climates, snow can fall but often melts before reaching the ground, resulting in rain.
What is the role of ice crystals and supercooled water droplets in precipitation formation?
-Ice crystals and supercooled water droplets are key to precipitation formation. Ice crystals grow rapidly in the presence of supercooled water, and they can aggregate to form snowflakes.
How does the temperature of the air beneath the cloud affect whether snowflakes reach the ground?
-If the air between the cloud base and the ground is no warmer than 2°C, snowflakes can reach the ground intact. If the air is above 2°C, the snowflakes will melt and fall as rain.
What are the most energetic cloud types that can produce heavy rain?
-The most energetic cloud types that can produce heavy rain are driven by strong convection, often resulting in cumulonimbus or thunderhead clouds.
How are hailstones formed and what is the process like inside a cloud?
-Hailstones form inside clouds as small ice crystals and water droplets freeze and aggregate. They can be carried up and down by warm and cold air currents, accumulating layers of ice and growing in size.
What is the largest hailstone ever recorded and where did it occur?
-The largest hailstone ever recorded was in Bangladesh in 1986, measuring 15 cm across and weighing over a kilo.
Outlines
🌧️ Precipitation and Its Formation
This paragraph introduces the topic of precipitation, emphasizing that it encompasses more than just rain and drizzle, including extreme weather events like hailstorms and blizzards. It explains that precipitation originates from clouds, which form when atmospheric water vapor cools and condenses into droplets or ice crystals, depending on the temperature. The paragraph discusses how different atmospheric conditions, such as warm and cold fronts, can lead to the development of various cloud types and subsequent precipitation. It also distinguishes between rain and drizzle based on droplet size and highlights the process of droplet coalescence in tropical climates versus the formation of ice crystals and snowflakes in colder regions. The paragraph concludes with an explanation of how snow melts into rain when it passes through warmer air layers before reaching the ground.
⛈️ Hailstone Formation and Severe Storms
The second paragraph delves into the formation of hailstones, which occur when small hailstones are carried up and down within a cloud by alternating currents of warm and cold air. This process allows the hailstones to accumulate layers of ice, similar to an onion's structure. The paragraph describes how, in severe storms, this can lead to the formation of large hailstones, with examples including golf ball-sized hail and the record-breaking hailstone from Bangladesh in 1986, which was as large as a tennis ball and weighed over a kilo. The paragraph encourages viewers to consider the complex journey of precipitation from water vapor to cloud droplets, and possibly to hail, before it reaches the ground as rain. It concludes with a prompt to visit the Met Office website for more information on precipitation, weather, and climate.
Mindmap
Keywords
💡Precipitation
💡Cloud Formation
💡Condensation
💡Ice Crystals
💡Supercooled Water Droplets
💡Aggregation
💡Glaciation
💡Anvil Clouds
💡Convection
💡Hailstones
💡Weather Fronts
Highlights
Precipitation includes not only rain and drizzle but also extreme weather events like hail storms and blizzards.
Precipitation forms in clouds where water vapor cools and condenses into droplets or ice crystals.
Clouds form when air is forced to rise, such as along a warm front, creating deep layers of clouds.
Cold fronts can push under warm moist air, lifting it and leading to cloudy skies with rain or snow.
Heated air rising from the Earth's surface can form cumulus clouds, which may develop into cumulonimbus clouds bringing heavy rain or hail.
Rain and drizzle differ only by the size of the droplets, with drizzle being composed of very small droplets.
Drizzle can reduce visibility significantly due to the small and closely packed droplets.
In tropical climates, the coalescing of droplets can produce heavy rain from deep clouds.
Ice crystals and super cooled water droplets mix in clouds below freezing, key to most precipitation formation.
Ice crystals grow rapidly in the presence of super cooled water, leading to the formation of snowflakes.
Snowflakes reach the ground intact if the air below the cloud is no warmer than 2°C.
In warmer conditions, snowflakes melt and arrive as raindrops when the air is above 2°C.
The most energetic cloud types, like cumulonimbus, are driven by strong convection and can produce heavy rain.
Glaciation occurs as water droplets freeze into ice crystals within the cloud, forming an anvil shape typical of thunderhead clouds.
Small hailstones form inside the cloud and can be carried up and down by warm and cold air currents.
Hailstones can grow layers of ice as they travel up and down within the cloud, resembling an onion when cut.
Severe storms with strong air currents can support hailstones as large as golf balls or even tennis balls.
The largest hailstone recorded, from Bangladesh in 1986, was 15 cm across and weighed over a kilo.
Understanding the journey of raindrops from water vapor to precipitation can enhance our appreciation of weather phenomena.
Transcripts
[Music]
[Music]
you might think that precipitation
sounds like a bit of a dull subject but
we're not just talking about rain and
drizzle we experience here in this
country it also includes extreme weather
such as hail storms and blizzards in
this film we're going to be looking at
those examples of extreme weather and
finding out how rain hail and snow are
formed all precipitation develops in
clouds and clouds are formed when water
vapor in the atmosphere cools and
condenses as the water vapor condens SES
it forms droplets and if the cloud
develops within or moves into a part of
the atmosphere that is below freezing
then the droplets form ice crystals the
cooling process which first forms clouds
can happen in many different ways air
may be forced to rise along a warm front
and as it cools deep layers of clouds
can develop sometimes reaching many
thousands of meters all the way down to
ground level air may also be forced to
rise as a cold front approaches in this
instance a wedge of cold dense air push
pushes under the warm moist air ahead of
it lifting it weather fronts tend to
bring generally Cloudy Skies with
relatively long spells of rain and
drizzle or SLE and snow at colder times
of year and finally air may be forced to
rise simply because it's heated by the
Earth's surface and it convex this is
what we often see on a summer's day with
cumulus clouds building up and sometimes
developing into towering cumon nimbus
clouds then we can get very heavy rain
and even hail let's look first at rain
and drizzle the only real difference
between rain and drizzle is the size of
the droplets drizzle is composed of very
small droplets half a millim or less in
diameter the tiny droplets that fall
from the cloud itself merge together or
coales until the droplet size becomes
large enough to fall from the cloud
under its own weight even though drizzle
is made up of small droplets it can
still produce some very poor weather
heavy drizzle can seriously reduce
visibility because the droplets are
small and close together in tropical
climates where deep clouds develop in
warm air this coalescing of droplets can
produce quite heavy rain but in our
latitudes anything more serious than
drizzle usually starts off as ice
crystals high in the atmosphere when
clouds build in air that's below
freezing we often get a mixture of ice
crystals and super cooled water droplets
that is water which is just below
freezing but hasn't yet turned to ice it
is this mix of ice crystals and super
cool droplets that is really the key to
understanding how most precipitation
forms the ice crystals are able to grow
rapidly where there is super cooled
water nearby because as soon as the
supercooled water makes contact with the
Ice Crystal it immediately freezes then
as the crystals drift through the cloud
they connect with other ice crystals in
a process called aggregation and large
snowflakes are formed this process of
aggregation can take place in any fairly
deep Cloud whether it's formed in layers
along a weather front or by the
convective bubbling up process
if the air between the base of the cloud
and the ground is no warmer than 2° C
then the snowflakes reach the ground
intact in warmer conditions when the air
beneath the cloud is above 2° C then the
snowflakes will melt and arrive on the
ground as rain drops this is the way in
which almost all significant rain is
produced in our latitudes it starts as
snow but melts before it reaches the
ground the most energetic cloud types
and the ones that can produce really
heavy rain are driven by strong
convection as the air cools the water
vapor condenses into water droplets
forming clouds as the cloud grows up
through the atmosphere it will soon pass
the freezing level and water droplets
within the cloud will freeze and form
ice crystals that is called glaciation
and an anvil shape is typical of cumulon
nimbus or Thunderhead clouds the fuzzy
edges of an anvil cloud show that there
are ice crystals present and the cloud
has grown well beyond the freezing level
these ice crystals grow as other water
drops nearby freeze onto their surface
creating a coating of ice and small
hailstones are formed inside the cloud
there will be rising currents of warm
air and some quite severe downdrafts of
cold air small hailstones may fall
through the cloud helping to create the
down drafts they can also be carried
back up through the cloud by the rising
currents of warm air this can happen
many times with the Hailstone melting
and freezing and developing fresh coats
of ice during its Journey Through the
Sub-Zero part of the cloud if you're
brave enough to venture into a hail
storm you can actually cut a Hailstone
in half and see how those layers of ice
are built up like an onion as the
Hailstone travels up and down within the
cloud in really severe storms that
process is repeated so often and the
currents of air are so strong that
hailstones as big as golf balls can be
supported in really severe storms
hailstones as big as tennis balls have
been recorded the largest hailstone ever
recorded in recent times came from
Bangladesh in 1986 six and measured a
whopping 15 cm across it weighed over a
kilo that's the same as a bag of sugar
next time you're out in the rain have a
think about what's going on above your
head and the journey those raindrops may
have made from water vapor into Cloud
droplets snow maybe even hail before
falling to Earth as rain if you want to
learn more about precipitation or
anything to do with weather and climate
visit the Met Office website
[Music]
Посмотреть больше похожих видео
5.0 / 5 (0 votes)