Be Weather-wise in Flying Kites

5.Strato-cumulus , large, lumpy masses or rolls of dull, grey cloud frequently covering the whole sky and sometimes giving it an undulating appearance'.
7. Stratus , 'a uniform layer of cloud, like fog in appearance but not lying on the ground'.
8. Nimbo-stratus , 'a low layer of structureless and rainy-looking cloud, sombre grey in colour'.
9. Cumulus , 'thick cloud whose summit is dome-shaped and exhibits protuberances, while the base is nearly horizontal'.
10. Cumulo-nimbus , 'great masses of cloud rising in the form of mountainous towers of which the upper parts, of fibrous texture, sometimes spread out in the form of an anvil. Clouds occur at different heights, and this fact is indicated by the use of the prefixes, cirro and alto. Cirro denotes those which are between 25,000 and 35,000 feet up; and alto those between 10,000 and 25,000 feet up. The lower layer occurs mainly between 500 and 7,000 feet up (Nos. 6-101)

Clouds and Weather

Generally speaking, the higher the clouds, the better the weather is likely to be; the lower the clouds, the worse it is likely to be. In particular, three factors to be taken into account are: movement, change and colour. The following are examples of these. Small cirrus clouds - 'mare's tails' - when they thicken and become lower, are a sign that rain is on the way. Cirro-cumulus-'mackerel sky'-heralds the approach of rain, and on occasions, of thunder. Cumulus clouds, when they expand early in the day, are also a warning that rain will fall later. Cumulo­nimbus becomes 'the thunder-cloud' when its top at the front becomes extended so that the whole cloud looks like an anvil. This may be accompanied by a sudden cool breeze, which travels in an opposite direction to that of the actual wind at the time. The cloud and the breeze are signs that a storm is about to break.

Clouds, however, are not only associated with rain and storm. They may also indicate fine weather. As an example there is the cirrus, previously mentioned, which now appears in a more pro­mising role. If it does not thicken and seems to be at a standstill or only moving slowly, in a region of high pressure, then it means fine weather. The 'fair weather cumulus' is another example. It does not grow bigger, has no marked upward bulges and moves slowly along. These are the clouds which are often to be seen on a warm summer day.