Did you know?
◎Sound travels farther before a storm
◎Ropes tighten before a rain.
◎Rainbows are always opposite the sun.
◎City temperatures are almost always 5 - 10 degrees warmer than the surrounding suburbs.
◎Clouds cover two-thirds of the earth.
◎Raindrops fall at speeds between 7 and 18 miles per hour.
For centuries, sailor and farmers relied on folklore(民间智慧) to predict(预测) the weather. As modern forecasting techniques became more accurate, most of these old tales were dismissed(不用了). But some have valid(有效的) scientific explanations.
Mackerel sky, not three days dry.
Mackerel sky refers to clouds that look like fish scales(鱼鳞). These cirrocumulus clouds(卷积云) are high, rippled(起涟漪的) ice crystals(结晶) that show up in advance of a storm system and may predict rain.
When dew is on the grass,rain will never come to pass.
The formation of dew(露珠) requires nighttime cooling(降温). This usually occurs best on cloudless, still(无风的) nights, so the chance of rain is unlikely.
Red sky at night, sailor's delight.Red sky in the morning, sailor's warning.
A red sky is the result of light passing through contaminants(污染物) held close to the earth by high air pressure(气压). These particles scatter away some of the shorter wavelengths(波长) of light (violets and blues), leaving only the longer wavelengths (the oranges and reds). A red sky is a reliable indicator (可靠的预示) of a high-pressure(高气压) system, which generally brings fair weather.
A red sky in the morning is the result of sunlight reflecting through clouds moving in from the west, which could bring bad weather.
Fish bite best before a rain.
The drop in barometric pressure(气压) before a storm sets into motion a chain of events(引起连锁反应): Bubbles formed by decaying products(腐烂物) on the lake bottom start to expand, making some of the matter buoyant(有浮力的) enough to rise. As minnows (淡水小鱼) start to feed on the rising matter, larger fish begin feeding on the minnows.
When a halo rings around the moon or sun, rain is approaching on the run.
The halo(光圈) is caused by refraction (折光) of light through cirrostratus clouds (卷层云). These clouds are similar to cirrocumulus, but they appear smooth instead of rippled. They indicate a possibility of an approaching storm system.
Mountains in the morning. Fountains in the evening.
Mountains refer to massive(大片的), cumulon-imbus(积雨云) morning clouds that indicate possible late-afternoon thunder-storms.