Red Sky At Night

                                                                                         

“Red sky at night, shepherd's delight. Red in the morning, shepherd's warning.”
This is probably the most famous of weather folklore and, as is so often the case, has been passed down through generations but has some basis in truth. As the sun sinks slowly down to the horizon at the end of the day, the colour of the sky depends on the nature of the air that the sunlight passes through. When the air is dry dust particles will be carried in the air absorbing and scattering the sun's light causing it to appear red.

Because of the spinning of the earth as the sun sets in the west this is also the direction of the prevailing winds, so in effect the sunlight is passing through air that is heading our way (this is for the mid-latitudes at least). So a red sky at night indicates drier weather on the way.
However a red sky in the morning indicates that the drier air is off to the east and it is likely that a front and more disturbed weather is heading in from the west. (This explains why the saying is more relevant to the mid-latitudes). So the shepherd's had it right all along!

There are of course many other weather sayings some of which have basis in fact, some of which are totally wrong (for instance cows do not lie down if it is about to rain!).
Another lore which could be a good guide is the idea of counting how many seconds elapse between a lightning flash and the sound of thunder to measure how far away a storm is. As it is the expansion of the superheated air around a lightning flash that causes the clap of thunder, and the speed of light (299,792,458 m/s) is so much quicker than the speed of sound (340 m/s), then this can be used as a rough guide.

Other weather folklore which have been built through generations of observation include:

“Rain before seven, fine by eleven”
“Clear moon, frost soon”
“No weather is ill, if the wind is still”
“when forest murmurs and mountains roar, close the windows and shut the doors”

One of the more interesting and popular weather lores is “It's raining cats and dogs”. The origins of this saying are difficult to trace. One theory is that cats and dogs (and other small animals) would live nestled in the warmth of a thatched roof. When it rained particularly heavily they would be washed out of the roof. Another idea is that heavy rains in the dirty streets of 17th century England would wash dead animals along the roads along with other debris. The animals hadn't fallen from the sky but this could have helped coin the expression.

However rational or obvious a saying may be, it can never 100% predict the weather. But these sayings have become part of our everyday language and it is easy to understand that in the past when people lived and worked on the land that these sayings would be very important to them as a very early means of predicting the weather.

About the author:
Mark Boardman
http://www.happyandwell.com
http://www.agloriousfuture.com

Article Source: http://www.Free-Articles-Zone.com