The picture above is what is known as a flammagenitus cloud and was pictured above the Australian bush fires. I had never heard of it before, so give me credit for the correct spelling of it.

Flammagenitus formations are like cumulus clouds formed when the surface of the earth has been heated by the summer sun. This causes the air to rise, forming water droplets and then big clouds.

In this instance, the heating of the earth by bush fires is what is causing the rapid formation of clouds. So when the heat comes from a local source like a fire or a volcano, a cumulus is known as flammagenitus or pyrocumulus.

If enough water vapour rises the cloud then becomes pyrocumulonimbus (say that after a couple of jars) which basically, is a thunder cloud. This in turn, can cause spectacular lightning displays that hit the ground and start more fires.

I have learnt two things from this:

1/ I didn’t know local sources of heat (bushfires or volcanoes) can cause thunderstorms.

2/ Spelling and pronouncing the names clouds is not for the faint hearted

Next week: Why do clouds have Latin names?