March 24, 2013

Head in the clouds

On the way back from a trip last weekend, we spotted this amazing cloud. The lower frill resembled cascading water. I had to veer off the Bruce Highway and dash to Deception Bay to get a better look. Ever in search of a roll cloud (see below), I dared to hope this might be the moment. I think, in fact, this was a shelf cloud, but I'm not a hundred per cent sure, and would love some advice from a seasoned cloud gazer.

I love clouds, even grey ones. Huge billowing thunder clouds, while they may be deeply disconcerting, are at the same time irresistible. Benign grey skies can provide a wonderful respite from burning hot blue. But not formless Tupperware, thanks. That's as oppressive as ever it was.
Tonight, we have had the most extraordinary storm: no fork lightning, thankfully, but almost continuous sheet lightning, which appeared green as the storm approached. There was another shelf cloud. It went dark an hour early thanks to this mother.
Clouds represent meteorological drama: they are portents; prophets. In the UK, we used to look up with dismay at a mackerel sky approaching towards the end of a summer's day: it meant the end of warm sunshine for a while. I love advancing frontal lines that herald weather that may be still back over the horizon but is inexorably on its way.
The photograph immediately above is one of my favourites: it's Brisbane-on-sea.

There are all sorts of creatures among the clouds. There might be a crocodile lurking in the CBD; a tropical sea monster guarding South Molle in the Whitsundays; or a polar bear-Chewbacca cross giving chase. Even Abe Lincoln came to watch the cloud show one day. Oh, c'mon: use your imagination.
Layering produces great colours.
Sometimes there are light shows...
Or interesting lines...
And then there's plain old drama. Once I saw a cloud drowning.
I have great cloud ambitions – mammatus, lenticular, barrel. And the most famous roll cloud of all – Morning Glory. A roll cloud is a low, horizontal cloud like a tube. It differs from a shelf cloud by not being attached to another cloud or associated with storm clouds. Morning Glory is the only roll cloud that can be predicted, roughly. Its formation depends upon frontal systems over central Australia, high pressure over northern Australia, and high humidity and strong sea breezes over the Gulf of Carpentaria and Queensland's Pointy Bit. It occurs between late September and early November: there may be one cloud or a series, each up to 1,000 kilometres long. Sometimes it occurs over land, but your best bet is from over the sea. I wish I could say I'd taken this image. Maybe one day...

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