Friday Sky Watch 5

The Poetry of Cloud Formation.

by Stephen Davenport

Hamlet: Do you see yonder cloud that's almost in shape of a camel?
Polonius: By the mass,and 'tis like a camel, indeed.
Hamlet: Methinks it is like a weasel.
Polonius: It is backed like a weasel.
Hamlet: Or like a whale?
Polonius:Very like a whale.

In this exchange from Act 111 of Hamlet, Shakespear might merely be using the whimsical nature of clouds to highlight the obsequious side of the courtier Polonius; but who has not,on a lazy day,watched the clouds changing from one form to another, hostage to the capricious wind?
On the face of it, August looks like it might have been an ideal month for this kind of indolance, having been the second cloudiest across the UK in 130 years of records.
Much of this cloud, though, was the featureless grey variety that simply does not lend itself to flights of the imagination.
Every now and then, though, we saw those showery days with the sun bursting out between bouncy white cumulus clouds, with a sharpe shower here and a rainbow there: the sorts of skies beloved of Constable, Turner and anybody who wishes to turn a mass of water vapour into, say, a sheep.
On such days the sky can be populated by a whole zoological garden of cloud species. And 'species'is the mot juste, both metaphorically and figuratively.
Most people are familiar with the broad categories of cloud or genera, such as cumulus, cumulonimbus, altocumulus and cirrus.
But these can be sub-divided into a species, and even further into sub-species or varieties.
For example, stratocumulus stratiformis opacus, the drab type of which we have seen so much.
A personal favourite rejoices under the classification altocumulus stratiformis translucidus perlucidus- or medium-level heaped cloud in a layer but of a translucent character with gaps between the cloud elements.
The traditional, more poetic, and far briefer, description would be 'mackerel sky'; but Luke Howard,a hero in meteorology in the 19th century, recognised the need for , and formulated, a more universal system based on the Linnaean pattern of classifications.
Howard's cloud sketches even inspired Constable; and Turner.
To many of us though, a cumulus will always look like a brassica oleracea- or cauliflower.