ATPL Meteorology - Class 8: Thunderstorms.
Summary
TLDRThis meteorology class explores thunderstorm formation, their dangers to aviation, and strategies for dealing with them. Thunderstorms, composed of cumulonimbus clouds, form under specific conditions like rising unstable air and high humidity. They pose significant risks to aircraft, including severe turbulence, wind shear, tornadoes, reduced visibility, and lightning strikes. The video emphasizes the importance of avoiding thunderstorms by at least 10 nautical miles and using weather radar for navigation, ensuring flight safety.
Takeaways
- 🌩️ Thunderstorms are formed by rising unstable air, high humidity, and a trigger like mountains or high temperatures.
- ✈️ They pose significant dangers to aviation, causing flight delays, aircraft damage, and potential injuries to passengers and crew.
- 🌟 Cumulonimbus clouds are the main components of thunderstorms, growing rapidly due to air instability and reaching heights that can form anvil shapes.
- 🌧️ The mature phase of a thunderstorm brings heavy rain and severe turbulence, which is hazardous for aircraft flying through it.
- 🌬️ Wind shear, a sudden change in wind direction and speed, is a dangerous condition near thunderstorms that can lead to stalling aircraft.
- 🌪️ Tornadoes can form from severe horizontal wind shear, which is extremely dangerous for aircraft and ground structures.
- 💧 Precipitation from thunderstorms can cause reduced visibility, water ingestion leading to engine failure, and hail damage to aircraft.
- ❄️ Icing is a hazard when supercooled water droplets freeze on the aircraft, affecting its aerodynamics and potentially causing handling issues.
- ⚡ Lightning poses an electrical hazard; modern aircraft are designed with a Faraday cage principle to protect against lightning strikes.
- 🛑 The safest strategy for dealing with thunderstorms is to avoid them by at least 10 nautical miles, using weather radar for detection, and delaying or diverting flights when necessary.
Q & A
What are the three stages of a thunderstorm's life cycle?
-The three stages of a thunderstorm's life cycle are the building phase, mature phase, and dissipating phase. During the building phase, a cumulonimbus cloud grows rapidly due to unstable air. The mature phase is characterized by precipitation falling and causing both updrafts and downdrafts within the cloud, leading to severe turbulence. The dissipating phase occurs when updrafts end and the cloud starts to reduce in size as the air becomes stable.
Why are thunderstorms so dangerous to aviation?
-Thunderstorms are dangerous to aviation because they can cause severe turbulence, wind shear, reduced visibility due to heavy rain or hail, potential engine failure from water ingestion, icing on the aircraft surfaces, and damage from lightning strikes.
How do warm weather thunderstorms form?
-Warm weather thunderstorms form when the heat from the air mass causes instability. The midday sun heats the air, making it unstable and causing it to expand and rise. This leads to the formation of cumulonimbus clouds and potentially thunderstorms, especially in hot and humid regions.
What is a squall line?
-A squall line is a long line of frontal thunderstorms. It occurs when a mass of cooler, denser air moves in and forces the warmer air upwards, leading to a continuous line of thunderstorms.
What is wind shear and why is it dangerous for aircraft?
-Wind shear is a sudden change in wind direction and speed that can occur near thunderstorms. It is dangerous for aircraft, particularly during low-level flight, because it can lead to a rapid decrease in airspeed, potentially causing a stall if the aircraft's thrust is not adjusted promptly.
How can lightning affect an aircraft?
-Lightning can cause electrical systems to overload and disrupt instruments in an aircraft. However, most modern jets are designed with a Faraday cage principle, which helps protect the electrical systems by allowing a lightning strike to pass through the aircraft's skin without interacting with the systems inside.
What is the safest strategy for dealing with thunderstorms in aviation?
-The safest strategy for dealing with thunderstorms in aviation is to avoid them whenever possible. Pilots should maintain a safe distance of at least 10 nautical miles, and if necessary, delay takeoff or landing until the storm has passed.
What is the role of the tropopause in thunderstorm formation?
-The tropopause plays a crucial role in thunderstorm formation as it is an inversion layer where the temperature stops decreasing with altitude. When a cumulonimbus cloud reaches the tropopause, it can no longer rise as easily due to the stable air, leading to the formation of an anvil shape at the top of the cloud.
How does the 'splash effect' contribute to the longevity of a thunderstorm?
-The 'splash effect' occurs when precipitation hits the ground and the air it cools is sucked back up into the cloud, especially on the side of the splash. This can help maintain the life of a storm by continuing to provide cool air, allowing a self-sustaining storm to last longer.
What are the two main types of thunderstorms mentioned in the script?
-The two main types of thunderstorms mentioned in the script are warm weather thunderstorms and frontal thunderstorms. Warm weather thunderstorms are caused by the heat of the air mass, while frontal thunderstorms are formed when a mass of cooler air moves in and forces the warmer air upwards.
Outlines
🌩 Understanding Thunderstorms and Their Dangers
This paragraph introduces the topic of thunderstorms, emphasizing their historical mystery and modern understanding, particularly in relation to aviation. It outlines the dangers of thunderstorms to aircraft, which range from flight delays to severe damage or injury. The narrator, Grant, sets the stage for an educational video on meteorology, focusing on the formation and dangers of thunderstorms. Key points include the necessity of certain conditions for thunderstorm formation, such as rising unstable air, high humidity, and a catalyst like mountains or high temperatures. The paragraph also explains the three stages of a thunderstorm's life cycle: the building phase with rapid cloud growth, the mature phase characterized by precipitation and severe turbulence, and the dissipating phase where updrafts cease, leading to the storm's decline. The potential for self-sustaining storms is also mentioned, where upper atmospheric winds can prolong the storm's life.
🔥 Types of Thunderstorms and Their Formation
Paragraph 2 delves into the two main types of thunderstorms: warm weather and frontal. Warm weather thunderstorms are linked to high temperatures and humidity, with the daily heat peak around 2 pm causing significant surface warming and leading to the formation of clouds and storms. Frontal thunderstorms occur when cooler, denser air masses force warmer air upwards, creating updrafts and the initial stages of storm development. The paragraph also describes squall lines, which are extensive lines of frontal thunderstorms that can pose significant challenges for aviation due to their size and the need to绕行 them. The hazards of thunderstorms are introduced, including turbulence, wind shear, tornado formation, and the various dangers they pose to aircraft operations.
⚡ Hazards of Thunderstorms in Aviation
Paragraph 3 discusses the specific hazards that thunderstorms pose to aircraft, such as turbulence within the storm, wind shear, and tornado formation. It explains how heavy rain can reduce visibility and cause engine issues through water ingestion. Hail is described as projectiles that can damage an aircraft, and icing is highlighted as a risk when supercooled water droplets come into contact with cold aircraft surfaces. Lightning, the electrical hazard of thunderstorms, is also covered, noting its potential to overload electrical systems. The paragraph emphasizes the importance of avoiding thunderstorms and using weather radar for navigation, as well as the potential need to hold or divert flights due to storm activity.
✈️ Navigating Aviation Safety Around Thunderstorms
The final paragraph summarizes the key points about thunderstorms, their types, and the associated hazards for aviation. It reiterates the importance of avoiding thunderstorms by maintaining a safe distance, the use of weather radar for navigation, and the potential need for flight delays or diversions due to storm activity. The paragraph also covers the three stages of a thunderstorm, the different types of thunderstorms, and the various hazards such as turbulence, wind shear, tornadoes, heavy rain, hail, icing, and lightning. The emphasis is on the safety measures that should be taken to avoid these hazards, including maintaining distance, delaying takeoff, and holding or diverting flights as necessary.
Mindmap
Keywords
💡Thunderstorms
💡Cumulonimbus Clouds
💡Tropopause
💡Turbulence
💡Wind Shear
💡Precipitation
💡Icing
💡Lightning
💡Squall Line
💡Weather Radar
Highlights
Thunderstorms were once so mysterious that gods were dedicated to them.
Modern understanding reveals the danger of thunderstorms to aviation.
Thunderstorms are formed by cumulonimbus clouds requiring rising unstable air, moisture, and a trigger like mountains or high temperatures.
Cumulonimbus clouds can rise rapidly, up to 60 knots, due to air instability.
Anvil-shaped clouds form when clouds reach the tropopause, creating a stable, flat top.
The mature phase of a thunderstorm involves heavy precipitation and severe turbulence.
Dissipating thunderstorms cease updrafts as rain pools colder air, reducing the cloud's size.
Self-sustaining storms can occur with strong upper atmosphere winds, causing splash effects and prolonged life.
There are two main types of thunderstorms: warm weather and frontal, each formed by different atmospheric conditions.
Warm weather thunderstorms are common in hot, humid regions and are driven by heat and humidity.
Frontal thunderstorms occur when cooler, denser air forces warmer air upwards, forming a squall line.
Thunderstorms pose hazards including turbulence, wind shear, tornadoes, and precipitation-related issues.
Wind shear can cause sudden changes in wind direction, leading to dangerous stalls at low altitudes.
Tornadoes form from horizontal wind shear, creating a destructive spinning effect.
Heavy rain reduces visibility and can cause engine failure due to water ingestion.
Hailstones can damage aircraft and reduce visibility, similar to heavy rain.
Icing occurs when supercooled water droplets freeze on contact with cold aircraft surfaces.
Lightning poses an electrical hazard, potentially overloading aircraft systems.
Modern aircraft use a Faraday cage principle to protect against lightning strikes.
The safest strategy for dealing with thunderstorms is to avoid them by at least 10 nautical miles.
Weather radar systems help pilots detect and avoid thunderstorms, especially at night.
If a thunderstorm is at the destination, holding or diverting may be necessary until it passes.
Departure delays are recommended when a thunderstorm hits the airport to ensure safety.
Transcripts
thunderstorms were so mysterious for so
many years that entire gods were
dedicated to them
nowadays though thankfully we understand
them a lot better and more importantly
understand how dangerous they are for
aviation
how are they formed and why are they so
dangerous though and what is the best
strategy for dealing with thunderstorms
should you encounter them
let's find out
[Music]
hi i'm grant and welcome to the eighth
class in the meteorology series
in this class we're going to be taking a
look at thunderstorms and why they are
so dangerous to aircraft in the best
case scenario a thunderstorm can result
in a few flight delays but in the worst
case scenario it can result in damage to
the aircraft or injury to passengers and
crew
these things are not to be taken lightly
and hopefully by the end of the class
you'll see why
a thunderstorm is made up of lots of
cumulonimbus clouds in various stages of
development
it therefore requires certain conditions
to form such as rising unstable air
it also requires lots of moisture in the
air or high humidity and something to
cause the air to rise such as a mountain
or high temperatures
in the first building phase of a storm a
small cumulonimbus cloud or cumulus
cloud will grow very tall due to the
instability of the air and can rise
rapidly upwards at as fast as 60 knots
if the grout if the cloud grows so tall
that it reaches the tropopause you can
get an anvil shape forming the sort of
flat top to the cloud
the reason this happens is because of
the inversion or isothermal layer at the
tropopause this means that a parcel of
rising air rising at the saturated
adiabatic lapse rate
will now reduce in temperature while the
air around it remains a constant because
of the tropopause
so the saturated air is now always going
to be colder than the surrounding air at
the tropopause
and therefore it is more stable and it
stops rising so you get this flat top
forming
after the building phase you enter the
mature phase this is when the
precipitation starts to fall this will
be in the form of large rain droplets
that are heavy enough to overcome these
large updrafts this large amount of
rising air
as the rain falls it will cool down
colder air with it as it goes causing a
mixture of both climbing and descending
air
and within the cloud itself within the
cumulonimbus cloud itself this would
cause severe turbulence if you were to
fly through it
the next stage after that would be
called the dissipating stage
this is basically when the updrafts end
the rising air
stops and this happens because the
falling rain is pooling down colder air
with it
so that means that the
saturated air is now often warmer
than the sorry colder than the
um surrounding air and it stops this
rising process from happening in this
stage there's basically no more updrafts
and the cloud will gradually start to
reduce in size with the precipitation
stopping as well
it is possible for a storm to sustain
itself if there are strong winds in the
upper atmosphere
this will cause the precipitation
and the associated colder air not
falling through the cloud itself but
actually falling in front of the cloud
this means there are only updrafts and
not the usual mixture of up and down
draw drafts to cause the storm to
eventually reduce in size
you also get a sort of splash effect
when the precipitation hits the ground
not in terms of the the water or the ice
particles the actual
precipitation itself
but that air that it cools down splashes
out on the surface
and on the side of the splash
with the
that is in the correct direction
to be sucked back up into the cloud and
help maintain the life of this storm
this means that a self-sustaining storm
can last a very long time
and the precipitation has the time to
grow in size and intensity forming large
hailstones for example or other extreme
weather conditions
generally speaking there are two main
types of thunderstorms you get warm
weather and frontal
so warm weather thunderstorms as the
name implies are caused by the heat of
the air mass itself and its effect on
the stability of that air
it's all dependent on the humidity
levels and temperature of the rising air
compared to its surroundings
if we have absolute instability of the
air where the environmental lapse rate
is cooling the environmental air at a
faster rate than any adiabatically
rising parcels of air it means that the
air partials are always warmer than the
surrounding air
therefore less dense and will rise up
during the warmest time of the day
around 2 pm the surface is nice and warm
and this heats up the air just above it
this causes an environmental lapse rate
that is more severe as there's a greater
difference between the temperature at
the surface when compared to the
temperature at altitude
this means at the surface there's a
large difference between the
dry adiabatic collapse rate and the
saturated adiabatic lapse rate when
compared to the environmental latch rate
this means that a rising parcel of air
is always going to be warmer
than the environmental air surrounding
it that means there's a high level of
instability
this high level of instability at the
surface leads to rising parts of the air
and that leads to formation of clouds
and thunderstorms
these types of warm weather
thunderstorms are very common in hot
humid places like southeast asia for
example frontal thunderstorms
are formed when a mass of cooler air and
more dense air moves in and as it moves
in it forces up the warmer air
the warmer air
being forced up causes updrafts pulls in
more air and it cools down and forms uh
the initial building phase of
thunderstorms and when you get a long
line of frontal
thunderstorms you can call it a squall
line
s-q-u-a-l-l squall line
and these can be
really
really long and you've got to fly miles
out of your way to get around them it
could be a real pain
thunderstorms are not nice things to fly
near and can lead to some seriously
dangerous flying conditions they're no
joke basically
there are many hazards associated with
them which we're now going to have a
quick look at
so the first of the hazards is
turbulence within the storm itself
we saw how
up and down drafts in the air can lead
to turbulence when we're in that mature
phase and surrounding the storm there's
also a lot of air getting sucked in and
coming out with the precipitation these
areas will have lots of moving air and
gusts which can lead to turbulence and
if you're between two storms you can
have
um a lot worse situation from this as
well when you enter into these areas in
your aircraft
from
the surrounding air you can get a large
and sudden change in direction and speed
of the wind this is known as wind shear
and it can be very hazardous at low
levels
say you're traveling forward at 100
knots with a tailwind of 10 knots
so you're going across the ground at a
speed of 110 knots
then you enter wind shear and suddenly
you have a 60 knot headwind instead of
that 10 knot tailwind
you would not then have the correct
thrust set and you would suddenly
experience a lot more drag without the
correct thrust which could lead to
stalling so you could go from 110 knots
along the ground and then suddenly
you're going 40 knots across the ground
huge change
just a quick search on youtube and
you'll find hundreds of examples of this
kind of thing a tornado can form when
you've got this wind shear in the
horizontal um
sense you can also get it in vertical
but if you have horizontal wind shear
and then it's got to be quite severe and
then that rising motion
sucks up the rising air as well the
horizontal
wind shear imparts a spin and the rising
air pulls up and you get the tornado
shape
and you don't need me to tell you how
dangerous tornadoes are they can destroy
entire towns let alone a small aircraft
so that's kind of the associated wind
hazards
in terms of precipitation hazards if
you've got heavy rain falling from a
storm it has the immediate effect of
reducing visibility there are windshield
wipers on planes but i'm sure as it's
happened to you when you're driving
along your car sometimes they just can't
keep up with the rain and you can't see
clearly
another issue of heavy rain can be water
ingestion
this means that the air being sucked
into the engine
is full of too much water and it can
actually put the spark
um
out in the aircraft and cause a flame
out and it leads to difficulties in the
gases in the engine lighting and the
engine could fail essentially if you've
got hail formed in a thunderstorm due to
the rising falling nature of the air
ice crystals will fall
um and hit the aircraft basically these
bullets flying at the aircraft causing
damage to the aircraft
this would
um obviously not be desirable and you
would have problems with visibility as
well just like you do with heavy rain
you can also get icing happening
this happens when supercooled water
droplets come into contact with the
aircraft and the temperature is low
enough
for regular water droplets icing is
normally considered a risk below about
10 degrees celsius as the aircraft will
be cold due to the surrounding
environmental air combined with that
wind chill effect and with super cooled
water droplets it's obviously always
going to be a risk
um as
and it's going to be more severe icing
when you compare it just to regular
water droplets below 10 degrees celsius
so we've got wind we've got
precipitation
the last one's what thunderstorms are
associated with most
lightning it's the electrical hazards
so lightning is the static discharge of
built up electricity caused by friction
it's a much more violent version of
rubbing your socks on a carpet and
touching someone to give them the
electric shock
the friction in this case the rubbing of
your socks is generated by the rising
and falling particles of air
if an aircraft is struck by lightning it
can cause electrical systems to overload
and problems with instruments and
anything else electrical to form
most modern jets are designed with a
faraday cage principle in mind which
means that the electrical systems are
insulated from the outside skin of the
aircraft and if a lightning bolt were to
hit
and it would pass through the skin and
not really interact with the electrical
system at all
but that's not all aircraft that's just
the big ones
you can also have static build up and
static discharge which is basically the
stage before full on lightning
and it can usually be heard as
static interference and crackling on the
radio systems and that can actually
interfere with your communications uh
with the ground you can't get a radio
calling because there's too much static
interference
and it's sometimes seen as a phenomenon
called saint elmo's fire which is a very
cool looking thing that looks like a
mini lightning storm on the windscreen
and the hazard here obviously arrives
from those communication issues
and in extreme in extreme cases saying
elmo's fire can actually crack the
windscreen
seen elmo's fire is worth a quick
youtube or google as well it's a very
cool phenomenon
the safest way to deal with a
thunderstorm is to avoid it
don't fly into a store unless you
absolutely have to and there is no other
option available
if it's daytime and you can see storms
simply maneuver around them at a safe
distance of at least 10 knuckle miles or
more
and if you have another option
if it's night time or to age you during
the day you can also use a system called
a weather radar
i won't go into the details of how they
work in full as it will depend on what
kind of aircraft you end up flying but
it's kind of like a sonar system you've
got a sweeping um
sonar that bounces back off of particles
droplets in the air and paints a picture
green orange red
of the severity of
the storms so at night time when you
can't see them you can still avoid them
using this weather radar and you would
have a predicted track line
and you would avoid them again by 10
knock miles or more
so that would be during the cruise but
if you arrive at your destination and
there's a thunderstorm overhead the
airfield you should consider holding
until the storm has passed or dissipated
the very nature of storms is that they
are not long lasting except in those
self-sustaining circumstances
and if this is the case diversion to
another airport may be necessary if your
fuel is getting low
and if you're about to depart an
aircraft
and a storm hits the best thing to do
again is just to wait until it's passed
it should be quite short in nature just
because that's the nature of storms
themselves but
in extreme cases i have to wait over
three hours one time before just because
there was one storm then the next and
the next
and one of the perks of the job you know
to summarize then you've got three
stages of a storm you've got building
mature dissipating building associated
with large amount of updrafts the cloud
building and building in size
and these can be very very
quick up to about 60 knots even more
the mature phase is associated with the
precipitation falling you get both
updrafts and downdrafts within the cloud
causing a lot of turbulence and the
precipitation will be large because it
had to overcome all of this strong
rising air
when that rain falls or that
precipitation falls it brings down
colder air with it and makes the air
more and more stable over time which
leads to this stopping and we enter the
dissipating stage where there's no more
rising air because the air is now
stable and we only have the down drafts
that coming off of it
and the cloud will reduce in size and
it'll fade out essentially
the only case where this doesn't happen
is when you've got a self-sustaining
system where you've got a strong wind in
the upper atmosphere that pushes the
rain outside of the cloud
so the precipitation or the rain falls
outside of the cloud so you don't get
this
cooling effect of the air this remains
unstable and the stable air is actually
located here you also get the splashing
effect of the rain feeding back into the
cloud only on one side but yeah
generally speaking two types of
thunderstorm we get warm weather uh
thunderstorms associated with heat
basically the midday sun heats up the
air makes it very unstable makes it
expand and
makes rising pockets of air
uh continue to rise creates absolute
instability and then you get frontal
storms
which is when a colder air mass moves in
underneath a warm air mass forcing that
up
and forms clouds and if you get a long
line of storms you would call it a
squall line there's many many hazards
associated with thunderstorms so they're
not very good things to fly through
turbulence you get the up and down
motion of the air
and turbulence can cause damage to the
aircraft in general and as well as
passengers crew everybody on board
wind shears when you get sudden change
in the direction
sometimes caused by this splashing
effect you suddenly fly in
to an area where the wind is a different
direction
and this is very dangerous when you're
low level because you could stall the
aircraft essentially you go from a
tailwind to a headwind do have the
correct thrust setting set
and you stall a tornado happens when you
get horizontal wind shear which imparts
a spin onto the air then it gets sucked
up by the rising air
and these are obviously very damaging
can damage and destroy whole towns if
they
get out of hand heavy rain when you're
flying near or underneath a cumulonimbus
or a thunderstorm has problems with
visibility you can't see your windscreen
wipers can't keep up and the engines can
also take in too much water and lead to
difficulties with the gases in the
engine lighting
and so you get an engine failure
hail you get the associated visibility
problems but also damage it's like
getting pelted with loads of bullets
icing ice can build up
from normal rain below about 10 degrees
celsius uh because of the wind chill
effect of the surfaces the surfaces will
be quite cold
and also with super cold water droplets
and it's going to be more severe icing
and ice buildup adds weight and it also
causes handling issues sometimes because
the aerodynamic surfaces have a
different shape if they're covered in
ice from normal you get electrical
hazards
static is a stage before lightning and
that would be associated with
communication errors kind of on the
comms side of things static crackling
that kind of thing and then when you get
the more severe lightning that could
shock whole entire systems but nowadays
there's a faraday cage principle applied
to most big aircraft
which means that a lightning strike will
kind of pass through the aircraft rather
than directly affect the electrical
systems and the big key thing with all
this is avoid thunderstorms by at least
10 nautical miles if not more
if you can give yourself 20 then why not
it's won't be that much more fuel and uh
the company will thank you a lot more
for burning a little bit more fuel than
for hurting a passenger due to severe
turbulence for instance
if you're about to depart
you will delay the takeoff
air traffic control will sometimes
enforce this so we say no departures for
the next hour that kind of thing but
you know be cautious
um if they don't have the rule in place
and on arrival to a destination you hold
if you're running out of fuel a
diversion might be needed to somewhere
where there's not a storm
but most importantly storms bad avoid
and
take
measures not to fly through them
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