Bunting is a sign of joy. Humans with an urge to celebrate often sew little triangles of cloth of different colours to a length of string, and then hang out their handiwork on high as a fluttering token of euphoria. And they call it bunting - but if you look the word up in a dictionary, it is clearly labelled "etym. unknown", which means that no one knows exactly where it came from.
But strangely, if you look up instead a German dictionary, you will find that bunt means "many-coloured", "variegated", "motley", even "gay". Every Easter, for example, the Germans like to paint their breakfast eggs in a wide variety of colours, and call them bunte Eier, or multi-coloured eggs.
If you look at the portrayal of a typical depression on a weather map, you will notice, trailing southwards from the centre, two bold curved lines tastefully adorned with little flags, just like a string of bunting. These are fronts. Leading the way on the south-eastern side of the low is the warm front, identified by solid semi-circular markings or delineated in red when the chart appears in colour.
The cold front bunting, shown in blue with pointed barbs, trails behind to form a triangular zone between the two, its apex pointing towards the centre of the low. This area between the fronts is called the warm sector, for the obvious reason that the air in this region is usually warmer and more humid than the air elsewhere.
As a low moves eastwards, its fronts are carried with it and swept anti-clockwise around its centre by the spiralling winds. Moreover, the cold front to the rear moves faster than its warm precursor, causing the warm sector to shrink in size as the days go by. Both warm and cold fronts may be thought of elongated zones of rain moving steadily across the surface of the globe from west to east.
The rain associated with a warm front sets in gradually. A cold front, on the other hand, is a much more lively entity, often bringing heavy and perhaps thundery, rain. And then, almost suddenly, a patch of blue may appear somewhere in the western sky, and then enlarge. The rain stops, the sun breaks through, and the wet, glistening countryside takes on a new look of brightness and of life.