Run For Cover: Hailstorms on Camera!

Hail is formed by severe thunderstorms and can range in size from super tiny pellets, which sound as though a mouse is tap-dancing on your roof, to massive grapefruits that plough straight THROUGH your roof. In this collection of three videos, we see just how large hailstones give tornadoes a run for their money in terms of the damage they can do.

For a more detailed account of hailstone formation, check out last week’s blog post: Goodness Gracious Great Balls of Ice!

Hailstorm Video # 1

This incredible video clip was filmed – mercifully – from the safety of a residential home. It records the deafening sound of massive hailstones slamming into the roof, as well as into the garden and pool. Note the huge splashes generated by the falling hailstones hitting the water and the size of the stones themselves as they accumulate on the grass.

Insurance companies in Oklahoma must have a very long and convoluted “Terms and Conditions” clause under the “Act of God” claim.

Video Source: “Hail Storm Oklahoma City” Uploaded by Beatlesfanxxl on May 16, 2010, YouTube Channel www.youtube.com/watch?v=OFv2W7Duqiw

Hailstorm Video # 2

Just when you think it can’t get any worse than having large chunks of ice smashing into your roof, porch, pool and garden vegetation, the intensity of the hailstorm swells. Suddenly, it LITERALLY starts raining branches, leaves and torn-up vegetation as this colossal hailstorm shows off its mettle. According to the person who filmed this video, the hailstones ranged in size from peas to baseballs and actually halted traffic on the interstate highways.

Thankfully, the kind of large hail produced by these large thunderstorms tends to fall in narrow swaths and as such, they rarely last longer than a minute in any one area. Still, though, that’s all it takes to leave you with enough yard cleaning to do for weeks!

Video Source: “Incredible Hailstorm Phoenix, Arizona” Uploaded by ChiliDog1723 on October 28, 2010, YouTube Channel www.youtube.com/watch?v=5XeTqp_HRIs

Hailstorm Video # 3

From beginning to end, this amazing hailstorm video shows the incredible damage done by hailstones the size of tennis balls as they smash into Woodson Texas soil, cars and even electrical cables. The guy filming it manages to pick up a couple of the hailstones to show us the size of these monsters in comparison to a quarter (US currency). Towards the end, an ambulance loads a patient who unfortunately got caught in the hailstorm and hopefully only sustained minor injuries. It just goes to show that, in storms the size and strength they are in the American Midwest, not even your car offers you sufficient refuge.

Video Source: “Very Large Hail” uploaded by Cld9trs on November 8, 2006, YouTube channel www.youtube.com/watch?v=wZr8jXo1Uso.

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Climate Change: A World Finally Warming Up To The Idea, PART 2

polar bear climate change global warming

Welcome to the second installment of this two-part series on climate change, Climate Change™, global warming and the many degrees of human idiocy that have generally resulted in a cluster you-know-what of misunderstanding on both sides of the debate. It’s the aim of this blog to discuss just why it is climatologists believe human activity (particularly our industrial activity) has and is causing global weather patterns and characteristics to change. In Part 1, we set the scene and provided the context for our debate by defining some key concepts in atmospheric science. If you haven’t read Part 1, SHAME ON YOU! All the same, here’s what you need to know all wrapped up like a delicious lightly toasted and seasoned McDonald’s McMuffin McMeal.

McDiabetes.

Important Terminology from Part 1

extreme-weather-climate-link-1-sandy
Union Beach, New Jersey: The devastation left behind by hurricane Sandy in November 2012. Source: News.discovery.com/earth/weather-extreme-events/

Weather: The day-to-day expression of the atmosphere as it is experienced on the ground. Look outside your window: is it raining today? It is sunny? Are you and your dog Toto en route to Oz on a twister? That’s what weather is.

Climate: The average weather characteristics of a region over a minimum period of 30 years. If it’s summer where you are, what weather do you expect to see outside your window? Do you expect it to be rainy because you live in the tropics and during summer it pisses down every afternoon? Do you expect it to be sunny because you live in southern California and southern Californian summers are like totally freakin’ awesome, hashtag #beach, like, yesterday, like oh my gaad! OR do you expect to be hitching a lift to Oz on a twister because you live in Oklahoma, which is a veritable super highway for summertime tornadoes?

THAT, my friend, is climate.

Climate change: A significant and lasting shift in average global weather and global weather patterns, which can take place over a time period of decades to thousands of years. It can be caused by all sorts of things, from variations in solar energy and plate tectonic activity to volcanic eruptions and meteorite strikes.

Climate Change: Significant and global scale changes in climate, weather patterns and characteristics caused by anthropogenic (human-originated) emissions of greenhouse gases. In other words, the stuff the movie “An Inconvenient Truth” was about.

Greenhouse gases: The atmospheric gases that absorb the thermal energy emitted by the sun and in doing so, contribute enormously to the warming of the lower atmosphere. Greenhouse gases include carbon dioxide, water vapor, methane, sulphur dioxide, ozone and nitrous oxide.

Great, now that you’re up to speed, let’s try to answer the following question…

Why Have We Buggered Things Up So Enormously?

Environmental destruction
Alberta Canada: Syncrude Aurora Oil Sands Mine. Not the kind of scenery you’d expect on summer holiday. Photo by Peter Essick for National Geographic.

The logic is simple. Greenhouse gases cause the warming of the lower atmosphere and because of this, they are very important to life on Earth. But, as it was mentioned in Part 1, too much of a good thing can be a bad thing. The persistent melting of Earth’s major ice sheets is direct evidence of the continued warming of Earth’s atmosphere.

arctic sea ice loss global warming
The loss of polar sea ice since 1980 according to the National Oceanic and Atmospheric Administration (NOAA). All of these model images show the size of the northern ice cap at the same time of the year. According to the Intergovernmental Panel on Climate Change (IPCC), there is a very real possibility that the Arctic summer will be completely free of ice by 2100.

Since the industrial revolution, when we discovered how to harness the energy released by burning coal, oil and other fossil fuels, the concentrations of carbon dioxide, methane, sulphur dioxide and other key greenhouse gases contained by our atmosphere have increased significantly. As each new discovery and development lead to the conception of newer and more sophisticated technologies, our output of greenhouse gases increased. Cars were once considered a luxury. Now, even beggars own Audis (true story; happened to me in Bahrain) and it’s not uncommon for the rich and famous to own more motor vehicles than they do teeth made from natural dental enamel and not gold.

The result of all the cars, industries, factories, refineries and other man-made technologies that require oil, coal, gas or petroleum is that we are relentlessly pumping out gases that are the by-products of burning fossil fuels. What I don’t understand is how anyone might expect this to NOT have an impact on our atmosphere and on its temperature characteristics.

Don’t The Forests And The Oceans Absorb CO2?

Environmental-Problems-Rainforest-Destruction
Active destruction of amazon rainforest to make space for the grazing of livestock

Yes! Plants, trees and other green things absorb CO2 at night, which definitely relieves the atmosphere of its burden of greenhouse gases. But look what we’ve done to them! What used to be verdant rainforest are now leveled, muddied and trampled pasturelands for cows. What used to be thriving woodland is now choked up with concrete, tar, brick and glass. There is only so much CO2 our dwindling green spaces can soak up.

What about the oceans? While they remain a massive sink (sponge, in layman’s terms) for CO2, the absorption of this greenhouse gas isn’t going without consequence. When you mix water and carbon dioxide, you get a weak acid called carbonic acid (H2CO3). And so, slowly, the oceans are becoming increasingly acidic. This is having a devastating effect upon the myriad of creatures whose shells are made out of calciferous compounds, from the beautiful coral reefs and their crusty citizens to Ariel the Little Mermaid, who will soon be swimming around topless without her bivalve bra.

Ariel the little mermaid

The more greenhouse gases you pump into the atmosphere, the more enhanced their effect will be. What is their effect? Warming, in theory.

Natural Variability Versus Anthropogenic Climate Change

The most infuriating argument put forward by people who don’t believe that mankind is having any kind of affect on our climate is that any evident changes can be attributed to the natural variability of our climate system. While it is true that Earth’s climate has undergone some dramatic shifts in the past – the premise for the movie Ice Age wasn’t thumb-sucked – these changes occurred over a time period of many thousands, if not tens of thousands of years. Natural variability typically takes a very long time to happen and the effects brought about by events, such as volcanic activity and meteorite impacts tend to be localized.

What we know is that global temperatures have changed at an unprecedented rate and that this change began around the time of the Industrial Revolution, which was only a few hundred years ago. Not a few thousand. In other words, the rate of change of global temperatures is unprecedented and there is a clear connection with the increased anthropogenic emissions of greenhouse gases, like CO2.

In even plainer, perhaps somewhat vulgar English:

Denying climate change is like pooping in the toilet and denying the presence of a turd.

How Do We Know All of This?

Ice core drilling Greenland
Ice core drilling in Greenland

Studying present and recent past climate has been made easier through the use of satellites, our vast array of ground weather stations and weather buoys. We have also developed the sophisticated computer software and modeling programs necessary to collate all of this data and provide us with a visual picture of climate, both past and present. But our historical records only date back a few decades, after which they become a little iffy to say the least. An appreciation of scientific rigor is something that was only cultivated towards the latter half of the 20th Century. So how do we know enough about historic climate to say anything about what’s normal versus what isn’t?

The answer lies in super deep deposits of ice, as one finds at the northern and southern poles, as well as borehole temperature profiles, deep layers of sedimentation and middens, which are accumulations of animal crap, urine, bones and shells in natural catchment areas. All of these and more reveal secrets about Earth’s history and in particular, the environment and the composition of the atmosphere at the time. By examining deep ice cores extracted from super-thick ice sheets at the poles, we are provided with a perfectly preserved timeline of the atmosphere’s carbon dioxide content (and other gases).

What we can tell from these sources is that natural variability is normal, but it happens slowly and that recent changes in atmospheric composition are happening at an unprecedented rate and are likely attributed to mankind.

If You Don’t Believe Me, Ask the IPCC

Intergovernmental panel on climate change

The Intergovernmental Panel on Climate Change (IPCC) is a global effort by climate scientists to present to the world and to world governments a robust and thoroughly researched report on global climate change driven by humankind. It’s essentially a document that is aimed at helping governments around the world understand and prepare their countries for the changes in weather patterns and characteristics that are anticipated as a consequence of climate change.

The opening paragraph reads:

“Climate Change 2013: The Physical Science Basis” presents clear and robust conclusions in the global assessment of climate change science – not the least of which is that the science now shows with 95% certainty that human activity is the dominant cause of observed warming since the mid-20th Century. The report confirms that warming in the climate system is unequivocal, with many of the observed changes unprecedented over decades to millennia: warming of the atmosphere and the ocean, diminishing snow and ice, rising sea levels and increasing concentrations of greenhouse gases. Each of the last three decades has been successfully warmer at the Earth’s surface than any preceding decade since 1850.”

You can read this and the rest of the report by clicking on This Link.

If You Don’t Believe the IPCC, Use Your Noodle

baby thinking hard

Anyone who has lived in a big to moderately sized city will know from personal experience that the climate in the city is typically different to the climate in the countryside. It’s hotter in the city during the day and it’s colder in the countryside at night. Generally speaking.

This is no accident… the type of land cover (vegetation versus concrete) influences how thermal energy from the sun is absorbed or reflected and this, in turn, has a great influence on average temperatures and temperature variation. The greater levels of pollution above a city also influence the temperature characteristics of the air. In fact, the greater number of small particles of dust, smoke and other pollutants in the air above cities can even cause clouds to form more readily, because these tiny particles offer water vapor a tantalizing surface around which they can condense.

None of this is a statistical projection spat out by some computer model and it isn’t the musings of some climate scientist pushing for government funding. It’s sound, solid fact and the kind of stuff you get taught in High School geography. THIS IS ANTHROPOGENIC CLIMATE CHANGE! Change brought about by human kind. It may be localized around major cities, but it is still noticeable to our skin and it is still change. The altering of the atmosphere’s temperature characteristics around our cities paints an irrefutable picture of how humans have changed climate.

Climate change on a global scale may be driven by different and/or more complex mechanisms, but to say that it is a natural, normal process that has nothing to do with our activity on this planet I find to be ridiculously ignorant. Tell me, do you enjoy sand in your ears? I think it’s dangerously erroneous to assert that we have not had an effect upon our environment, which includes the ground beneath our feet as much as it does the air above our heads… and in some people’s cases, in their heads.

George bush jr thinkingClass Dismissed: Your Take-Home Message

Over the many decades since the Industrial Revolution, we have pumped billions of tons of carbon dioxide, methane, sulphur dioxide and other greenhouse gases into the atmosphere. We’ve changed tens of thousands of square kilometers of our planet’s essential land surface characteristics by leveling forests for agriculture and allowing livestock to raze grasslands to the ground. We’ve polluted water sources, wiped out thousands of different animal and plant species and pretty much made a total mess of our natural environment. We have had a definitive impact upon planet Earth and no one in his or her right mind can debate that point.

pollution global warming

It has been the aim of this two-part series is to unravel the knotted, warped information we are fed by the media and help us regular folk better understand it: to see through the sensationalist claims to the logical, underlying science. Climate change has become a media buzzword and a vastly popular issue that has been the driving point of many political campaigns in first world nations (*cough*America*cough*). It has become a passionate, political issue and as a result, sides have been created: those who believe we’ve caused our climate to change and those who don’t.

What I want you to do is to look through all the bullshit of BOTH sides of the argument and ask yourself the following question: am I surprised that our ruthless industrial activity and atmospheric pollution has caused global climate to change?

Whether you trust what the scientists say or not, you simply can’t say no. And if you do, I challenge you to tell me why.

extreme-weather-climate- global warming

The Sky Is Only Sometimes Blue

Beautiful sunrise

If asked what colour Earth’s sky is, you wouldn’t be unforgivably wrong to answer that it’s blue. A more correct answer, however, would be “it’s blue, sometimes”.

Earth’s sky is black at night and grey in overcast weather. It’s brilliant crimson, orange and yellow at sunset, and a sultry blend of indigo, violet and pink at dawn. Around noontime on clear days, it’s white at the horizons and on brooding, stormy days, when there is a promise of severe thunderstorms and hail, it can be slate grey with a slight tinge of green.

The sky is many colours. It’s only sometimes blue. Ever wonder why? Doesn’t matter, I’m going to tell you anyway and what better place to start than by shedding some light on… light!

What Is Light?

Rays of sunshine breaks through the clouds

What we know as light really only represents a fraction of the full spectrum of energy radiated by the sun and the other stars in our Universe (and other possible Universes). Visible light is the narrow range of electromagnetic energy that can be seen by humans and is responsible for illuminating our world in a cacophony of beautiful colour. It’s made up of teensy particles called photons (think photography, meaning “light”), which, unlike gas molecules, don’t float about arbitrarily bumping into the sides of objects like pong balls. Rather, photons travel in waves, just like nausea after some bad Chinese.

Waves are awesome for more than just surfing. They have all sorts of physical properties that, once understood, give us the key to understanding the behaviour of sound and light and our perceptions thereof… such as the colour of the sky!

Like, Wave Properties, Man

Cool surfing goat

Any (serious) surfer will tell you that waves have many properties, including height, amplitude, energy, frequency and wavelength. These are all measurable quantities that can be applied to ALL kinds of waves, including energy and sound waves. For this particular topic, however, we shall be focusing on a property called frequency.

The frequency refers to the number of waves that occur in a given time period. So, imagine you’re sitting on a cliff that faces out to sea. In a period of one minute, you count every wave crest that passes your direct line of sight. The number of crests you count per minute is the frequency. Sounds pretty simple doesn’t it? Now try counting the light waves that are bouncing off your dad’s horrible Hawaiian shirt. Obviously you can’t. We can’t see light waves, or sound waves for that matter, but we CAN perceive the differences that arise as a result of differences in their frequency.

High and low frequency waves

Sound waves with a high frequency (refer to the above diagram with the squiggly lines) are perceived by our ears to be high-pitched. Like the sound your wife makes when she gets mad at you for leaving your cheesy socks next to the bathroom sink. Sound waves with a low frequency are perceived by our ears to be low-pitched, like Barry White’s crooning. Similarly, light that travels at a high frequency is perceived by our eyes to be blue or violet and light with a low frequency, as red or orange. In between, you’ll find green and yellow. Together, they all make up the gay flag!

Visible light spectrum
The above spectrum shows the variation of colour as determined by the frequency of the visible light emitted by the sun (or any star). Violet and blue lie at the extreme high-energy end of the colour spectrum, while red and orange lie at the low-energy end.

As it was initially explained, visible light represents a mere fraction of the full range of energy produced by our star. The “electromagnetic spectrum” may sound like a horribly complex term, but you’ve actually met most of the members of the family! Let’s take a look… Take a deep breath. It’s not complicated. I believe in you!

The Electromagnetic Spectrum

Electromagnetic spectrum

The squiggly line in the middle represents the size of the wavelengths of the various “kinds” of electromagnetic energy, from the low energy radio and microwaves (that you use to heat up your TV dinners) to the high energy X-ray and Gamma rays (that you definitely don’t use to heat up your TV dinners).

Slap bang in the middle of this diagram, you will see the blue box titled “visible”. This is visible light and it refers to a range of energy frequencies that account for all the colours we see and, in general, the light that illuminates our world.

Now, as we move to the right of the spectrum, the waves become more energetic and the frequency increases. Electromagnetic radiation becomes ultraviolet and then X-ray, as is used in medical diagnostic technology to reveal your bony insides. Finally, at the high-frequency end of the electromagnetic spectrum, we get gamma radiation, which is so ridiculously energetic that a minute’s exposure would either incinerate you, or cause such terrible mutation of your cells that you’d turn into Joan Rivers.

Joan Rivers

Thankfully, the gamma radiation produced by the unending nuclear fusion reactions in the heart of the Sun doesn’t quite make it to the Sun’s surface and so, our little planet is safe. Earth’s ozone layer also manages to deflect much of any high-energy radiation that heads our way from other locations in the universe, except for small amounts of UV light, which can cause sunburn and melanoma, amongst other kinds of skin cancers.

But, how on EARTH does this all link back to the colour of the sky?

By understanding how the frequency of visible light determines its position on the colour spectrum, we are given the key to understanding the colour of the sky!

Why Is The Sky (Sometimes) Blue?

animated-blue-sky

When visible light reaches our planet, it encounters all the trillions of molecules of gas, water and other particulates that are so abundant in the atmosphere. While the majority of the spectrum can travel through this veritable obstacle course unscathed, blue light is unlucky enough to be of the perfect wavelength or “size” and so can’t help but collide with all these molecules and particles.

It’s like trying to roll a marble (blue light) tennis ball (green light), skateboard (yellow light), bicycle (orange light) and car (red light) through a car park FULL of marbles. Which one do you think it going to have the greatest difficulty getting from A to B without being deflected off its path? Blue light obviously and as a result, it gets scattered off its original course, which is what we see when we look up at a blue sky. This effect is known as Rayleigh scattering and is named after the obnoxiously titled English physicist, John William Strutt, 3rd Baron Rayleigh Peacock Eminent La-di-da.

In reality, more than just blue light is scattered. A little bit of violet and green and even red light is scattered, too. But it’s predominantly blue that has fender benders across the daytime sky. If you throw a teaspoon of violent, green and red into a bucket of blue paint, the resultant colour will still be blue. This all changes, however, as the sun carves its path across the sky, drawing inexorably closer to the horizon…

Red, Orange and Yellow Sunsets

Beautiful sunset
Sunset over the Satara Rest Camp, Kruger National Park.

From our perspective, the atmosphere at the horizons is thicker owing to the oblique angle at which we are looking at it. The following two diagrams illustrate this point beautifully, saving me a fair amount of wind…

Light entering Earth's atmosphere

Light entering Earth's atmosphere 2

In the first image, the length of the path the sunlight travels to reach the little sunbathing dude, as denoted by the black arrow, is much shorter than in the second image, when the sun sits on the horizon. This longer distance means that by the time the light finally does arrive at the dude’s eyeballs, all the blue light has been scattered out, leaving only the low-energy frequency light: reds, oranges and yellows. This is why sunsets look like sex-on-the-beach cocktails.

It’s also why they inspire cocktails… and sex on the beach.

Interestingly, at midday, the light travelling to us from the horizon still needs to claw its way through a thicker layer of atmosphere. While this light IS scattered red light, its mixture with all the blue scattered light from the rest of the sky causes the one extreme end of the colour spectrum to meet the other, effectively cancelling each other out. The resulting colour is white. In other words, at the horizons, all members of the visible colour spectrum are reunited, leaving you with *drumroll* white light.

Why Are Some Sunsets More Spectacular Than Others?

Beautiful red sunset

Discounting the sunsets you watched while totally baked on that good shit your cousin somehow smuggled in from Canada, the more spectacularly hued sunsets can be attributed to the composition of the atmosphere.

The more particles there are in the sky, be it dust, pollution, smoke, water vapour or the workings of a local volcano with indigestion, the more aggressive the scattering and the more enhanced these effects will be. This explains why there is nothing more beautiful – implications aside – than a sunset over a horribly polluted sky.

Cloudy With A Chance Of Green

Green thunderstorm clouds

There is a strange greenish tinge to the sky that can sometimes develop just before a severe thunderstorm drops its load. It’s especially noted with powerful storms that are able to form large hail and tornadoes. I’ve heard two theories explaining why this happens, but it would seem that the jury is still out on which one is more correct:

  1. Severe thunderstorms typically occur during the latter half of the day and especially towards sunset. These kinds of thunderstorms also form very high cumulonimbus towers and the abundant water vapour within these clouds sends blue light scattering like skittles on a waxed floor. With the sunset throwing red scattered light on the blue underside of the clouds, the resultant visual effect can be a greenish tinge, as you can see in the picture above.
  1. The other explanation is that the presence of large hailstones within a thundercloud can actually scatter light whose frequency is slightly lower than the standard blue. What colour comes next after blue? Green of course, hence the greenish otherworldly tinge. I prefer this explanation since it’s more awesome.

Having said all this, a greenish sky is not a sure-fire indicator that a tornado is on the way, as is a popular myth amongst the residents of Tornado Alley. But it does indicate the presence of a very tall convective storm, which you can pretty much bank on ruffling a few leaves. Maybe even relocating a cow.

Class Dismissed: Your Take-Home Message

Beautiful yellow sunset
Sunrise, somewhere in the middle of the beautiful South African nowhere

The sky appears to us in a myriad of colours throughout the day and it all comes down to the fact that visible light has multiple personality disorder. Whichever colour you do see is a result of that particular frequency of light being scattered more effectively than the others. But our foray into the physics of light has explained more to us than just the hue of the sky… it has also revealed just how many fascinating things wave properties account for, from the pitch of your irate wife’s voice to Indian Ocean tsunamis.

I intend to explore both of these in good time, but in the meanwhile…

What personality is your sky right now?

colour-spectrum-wallpaper-HD

Goodness, Gracious Great Balls of Ice!

Large hailstone damage

Some things on our planet are so ridiculous that when you really think about them, it’s enough to make you go biblical. Frogs falling from the sky, crop circles, giant swirling hurricanes, belching volcanoes, sulphur-based life forms and Paris Hilton’s immense wealth (and equally as immense lack of IQ). And then there’s hail. The fact that the updrafts within a thunderstorm can be strong enough to hold grapefruit-sized hail in suspension is nothing but ridiculous and wholly impressive.

Great balls of ice!

How Hail is Made 

Falling hail thunderstorms

Hail consists of balls of ice shockingly called “hailstones”. You may even say that hail is frozen rain, but it deserves a slightly more complex explanation than that…

Hail is made within powerful thunderstorms or cold fronts. Cold fronts tend to produce smaller hail that might inconvenience your dog’s plans to go do his business outside (thereby inconveniencing your plans to keep your house hygienic). The large hail responsible for denting cars, destroying crops and severely upsetting your heard of cows is typically associated with large thunderstorm systems that are well-endowed in the vertical and are sustained by powerful updrafts. These traits are especially exhibited by the “Big Daddy” of all small-scale tempests: supercell thunderstorms. These you will find all over the world, but most notoriously skipping across “Tornado Alley” during the northern hemisphere’s summer months.

Supercell thunderstorm
Supercell thunderstorm with rotating mesocyclone (*swoon!*). The presence of such large frozen water particles within the cloud selectively reflects light towards the lower energy (green) end of the color spectrum, which is why thunderstorms that produce large hail tend to make the sky appear a ghostly green.

What cold fronts and thunderstorms have in common is that they are both low pressure systems that suck in air and expell it out their rear. Thunderstorms pull in great volumes of warm and moist air, which rise, cool and condense to form towering cloudy behemoths. Yes, cumulonimbus clouds. The air, once cooled, loses its momentum and proceeds to sink towards the ground. Together, these two channels of air comprise the updraft and downdraft zones that sustain a thunderstorm: its lungs if you’ll indulge a bit of poetic licence.

Now, as you know, temperature decreases with height in the atmosphere. That’s why the tops of high mountains are frozen and it’s why you should always, ALWAYS go for a pee before sky diving. At a certain altitude within a thunderstorm, which can soar to as high as the interface between the troposphere and stratosphere at approximately 10 km above sea level, the temperature reaches zero degrees Celsuis – the temperature at which water freezes. Above this 0°C isotherm (an obnoxious way of saying “line of equal temperature”) all the water droplets in suspension are frozen.

The strong updrafts within a thunderstorm sweep water droplets above the 0°C isotherm where they freeze (consult the pretty diagram below). These pellets of ice then fall back down towards Earth in the downdraft zone, plummeting below the 0°C isotherm and defrosting into big globs of water. This is why thunderstorm rain gets you soaking wet in 10 seconds flat. Just like Channing Tatum in “Magic Mike”.

hail-formation-diagram

However, some of these falling frozen pellets of rain get caught up in the updraft zone again and are swept back up above the 0°C isotherm. Only, they’ve gained a layer of water, which they collected as condensation while chilling out below the 0°C isotherm. This additional layer of moisture freezes, forming a new layer of ice over the original ice pellet.

Concentric layers of ice_hailstone
Concentric layers of ice in a hailstone. Just kidding! It’s a microscopic image of a bacterium’s nipple.

This process can repeat itself several times and each time, the hailstone will grow larger and larger and larger as it collects more and more layers of ice. The next time you’re in the middle of a raging supercell storm, run outside, collect a couple of decent-sized hailstones, run back to the tornado shelter, bolt the trapdoor, watch your dad arm wrestle said trapdoor with an F5 tornado, watch your dad lose, resolve to become a hardcore white vest-wearing, tornado chasing sexpot with a serious deathwish. Oh! And remember those hailstones you collected? Cut them open to see those concentric circles of icy awesomeness.

When a hailstone finally gets too heavy for the thunderstorm’s updrafts to hold in suspension depends entirely on the strength of those updrafts. The stronger they are, the heavier the hailstones. This is why larger hailstones are associated with powerful thunderstorms, such as the Midwest supercells that are sustained by incredibly strong updraft zones.

And when hailstones get heavy, it’s time to run for cover.

large hailstone damage

 Sorry Boys… Size Really Does Matter

Farmers are more obsessed with size than that clutch of vacuous floozies and jockstraps in Jersey Shore. Considering their livelihood depends on it (and not their egos), this is easy to understand and empathize with. But, in no other aspect are they more obsessed with size than with hail. The happiness and health of their livestock and crops depend on it.

Some thunderstorms can create hailstones that are big enough to cave your head in. Even if you do have brains. The next time you’re at a party, scoop an ice cube out your rum and coke and toss it at your mate (preferably the one who’s hitting on your girlfriend). Listen to the dulcet sounds of squealing as it clobbers him in the noggin. Now imagine something easily ten times the size of that ice cube falling thousands of metres (or feet) from the heavens. Yup! Ouch.

Largest hailstone on record
Ermagherd! Ferkerng HUGE herlsterne!

On 23rd June 2010, the largest hailstone in recorded American meteorological history fell in Vivian, South Dakota (image above). This great ball of ice weighed in at 0.88 kg (1.93 lbs) and was a staggering (if it had hit you in the head) 20 cm (8 inches) in diameter.

That’s two inches longer than your average you-know-what, tee hee!

 Class Dismissed: Your Take-Home Message

hail_storms-on-road

Hailstones are physical evidence of the incredible air circulations going on inside a thunderstorm. Can you imagine how strong air must be to prevent something that weighs almost a kilogram from succumbing to gravity? I don’t know about you, but that blows my mind in the most delicious way. And so we see that thunderstorms are about so much more than just thunder and lightning and the occasional airborne cow. These bad tempered weather systems can also be that jerk at a party who throws ice at you.

But, then again, you were chatting up his cherry.