We have been attempting to forecast the weather since the beginning of recorded history. Long before the invention of radar and other meteorological tools, people relied upon "natural" clues to approaching weather. Many of these have a scientific basis and it can be explained why they "work," others have no such basis but often prove to be true.
Perhaps the most often quoted weather proverb among mariners is:
Red sky in morning, Sailors take warning.
Red sky at night, Sailors' delight.
A red sky at night (when the sun is to the west) is caused by light passing through dust particles in the air to the west. Dust indicates dry weather and since most weather changes come from the west, a red sky at night usually indicates dry weather approaching. A red sky in the morning, however, indicates that the dry air has moved away. A gray sky at night means that the western air is filled with moisture and it will likely rain soon.
The first recorded use of this system of weather forecasting can be found in the Bible. In Matthew 16.2-3, Jesus says to the fishermen, "when it is evening, you say, 'It will be fair weather, for the sky is red.' and in the morning 'It will be stormy today, for the sky is red and threatening." Since it has lasted so long, we think there must be something to it.
Other variations on this theme include:
Evening red and morning gray, help the traveler on his way.
Evening gray and morning red bring down a rain upon his head.
Rainbow in the morning
gives you fair warning
The sun is in the east in the morning, the shower and associated rainbow are in the west. Since weather generally moves from west to east, rain is approaching.
Beware the bolts from north or west;
In south or east the bolts be best.
Same reasoning as the above.
Rainbow to windward, foul fall the day;
Rainbow to leeward, rain runs away.
If the wind is coming from the direction of the rainbow, the rain is heading toward you. Conversely, if the rainbow is in the opposite direction, it has passed you.
Mackerel skies and mares' tails
Make tall ships take in their sails.
Cirrus clouds (mackerel skies or clouds that looked as if they'd been scratched by a hen, according to the old-timers) often precede a warm front which brings winds and rain.
When halo rings the moon or sun
Rain's approaching on the run.
The halo is caused by high cirrostratus (ice crystal) clouds that are indicative of an approaching warm front and predict rain within 20-24 hours. The U.S. Weather Service confirms that rain follows about 75 percent of sun halos and about 65 percent of moon halos.
The higher the clouds
the better the weather
These clouds generally indicate both dry air and high atmospheric pressure - usually associated with fair weather. Lowering ceilings indicate rain.
A wind from the south
has rain in its mouth
A south wind blows in advance of a cold front and also blows over the east quadrant of an approaching low pressure cell.
Seagull, seagull, sit on the sand,
It's a sign of rain when you are at hand
In general, birds roost more during a period of low pressure. Before a hurricane, flocks of birds will be seen roosting. Take off may be harder when the pressure is low or the air is thinner because the natural updrafts are lessened.
Some weather proverbs published in 1883 by the War Department (no explanation given):
Buzzards flying high indicate fair weather.
One crow flying alone is a sign of foul weather; but if crows fly in pairs, expect fine weather.
When porpoises and whales spout about ships at sea, storm may be expected.
Two full moons in a calendar month bring on a flood.
Comets bring cold weather.
If shooting stars fall in the south in winter, there will be a thaw.
Lightning under the North Star will bring rain in three days.
And one that warrants further investigation:
When the bubbles of coffee collect in the center of the cup, expect fair weather. When they adhere to the cup, forming a ring, expect rain. If the bubbles separate without assuming any fixed position, expect changing weather.
Thanks to Norman Westrick for addressing a possible answer to this often quoted, but perhaps less understood, weather proverb.
As Im sure you know, liquids have surface tension. They also tend to adhere to objects. That is why you can fill a glass to just a little over the top without it spilling.
When coffee is hot, it creates a small amount of pressure on the under side of the surface. If the barometric pressure is low, the pressure in the cup (created by the heat) will overcome the atmospheric pressure and cause the surface of the coffee to be convex and the bubbles will settle to the edge of the cup. Low barometric pressure indicates weather deteriorating.
If the barometric pressure is high, the pressure in the cup will be depressed by the atmospheric pressure and the surface of the coffee will be concave and the bubbles will settle to the center of the cup. High barometric pressure indicates clear weather.
The last part of the proverb (bubbles separate without assuming any fixed position) would be when the barometer is on its way up or down and has found that happy middle ground where the pressure above and below the surface of the coffee is about the same.
So what do you think, sound plausible?
Related Articles: Weather 101