All about Killer Clouds

Have you ever noticed how something beautiful to be found in nature can be often very dangerous even lethal?

The term “killer cloud” is a generic name given to the often stunning Cumulonimbus clouds associated with the devastation and death caused by the effects of heavy thunderstorms and lightning.

Cumulonimbus , or storm clouds, are recognized by their “puffy appearance”, having flat bases and rounded domes . They can vary in size and appearance and can develop into huge, concave shaped clouds that go on to give us the heavy thunderstorms and the radiating branches or “streaks” of lightning that we have come to admire yet fear.

Windy conditions cause the clouds to form lines in conjunction with the wind. These are known as cloud streets which occasionally form droplet shaped patterns when the wind driven clouds come up against a barrier.

If you observe cumulus clouds over the sea, you will notice that they are spaced in regular lines, with the most notable examples being found in the “trade winds” where their coverage is extensive.
Cumulonimbus are formed from cumulus at a much lower height allowing them to form a typical “mushroom” shaped mass. The cumulonimbus can measure several miles across, and can occupy both low and middle altitudes initially forming at an altitude of between 10,000 to 12,000 feet, peaking to a height of up to 75,000 feet.

Types of cumulonimbus clouds:

Cumulonimbus calvus- large cloud with puffy top lacks the familiar anvil or flattened top.

Cumulonimbus praecipitatio: Precipitation which has rain, hail, snow in shower form.

Cumulonimbus capillatus – cloud with fibrous cirriform appearance in its upper parts or streaky cloud mass.

Cumulonimbus virga: Has drop strips

Cumulonimbus pannus: Rough patches beneath cloud.

Cumulonimbus incus – Similar to Cumulonimbus capillatus, with a flattened appearance

Cumulonimbus mammatus: Sac-like, wart-like excrescences at the bottom side of the cloud.

Cumulonimbus pileus: Capped

Cumulonimbus velum: Veiled

Cumulonimbus arcus: Has a gust collar at the bottom side of the cloud.

Cumulonimbus tuba: With funnel cloud or tornado

Although these clouds are known as “killer clouds”, they can still bring useful information from the knowledge we have through the development of its many structures. Mostly you will have a good idea of when rain is coming but occasionally it can act as an early warning system or a tool for fact gathering by “storm chasers” or meteorologists to predict dangerous weather conditions.

The terminology “killer cloud” can also be applied to a number of other situations and has been used as an analogy to aptly describe specific moments in history that have been affected by “cloud like formations”

An example of this can be seen when the volcano Laki in Iceland erupted in 1783 and produced a huge toxic cloud of sulfur dioxide and sulfuric acid that extended across Western Europe. It lasted eight months in total and killed many thousands of people.

There are only three lakes in the entire world, Nyos, Monoun, and a third Lake called Lake Kivu on the border of Congo and Rwanda, that accumulate deadly amounts of dissolved CO2 at great depths. From time to time these gases are emitted into the atmosphere as the result from a build up of pressure deep within the lakes themselves.

A famous incident in 1986 documents how one of these toxic clouds were responsible for the deaths of nearly 2000 people at lake Nyros in Cameroon. Caused by the emission of pent up CO2 gases from underwater fissures, scientists and engineers remedied the problem by installed a pump and a tube to help release the build-up of the dangerous gas. They are now considering shoring up the natural dam with concrete, and installing more siphon tubes do reduce the CO2 much more quickly, to achieve safe levels within four years.

The term “killer cloud” can also be applied to man made disasters such as the 1952 Great Smog in London, England. Although famous for its “pea-soupers” since the advent of the Industrial Revolution, this particular killer was made up of clouds of soot and coal. Initially forming as a dense, freezing fog, people reacted by burning more coal to offset the cold. This caused the cloud to become thicker, stretching itself over the entire capital for 4 days in total.

It brought the city to a complete and the insidious fumes crept inside the houses and public buildings, killing 12,000 people in total by suffocation or causing respiratory complications. The victims from that period were said to be found walled up in their homes for many years afterwards.