Reading the Sky　觀天知天氣

史蒂夫·努比　俞月圓

Long before the weather channel， our pioneer ancestors and native tribes looked for signs in nature to forecast the weather. The sky was their primary focus， but how the sky， air， and barometric pressure affected plants， animals， and people were also tell-tale signs.

Over time， simple sayings evolved to remind us of the weather to come， although some of them arent so accurate from a scientific standpoint.

Weather sayings from folklore：

Red sky at night， sailors delight; Red sky at morning， sailors take warning.

When ditch and pond offend the nose， look for rain and stormy blows.

Chimney smoke descends， our nice weather ends.

A ring around the sun or moon， means rain or snow coming soon.

Rainbows in the morning give you fair warning.

Its one thing to remember some old adages， but its easier to remember if you understand the science behind the sayings.

Reading the smoke

Smoke from a fire can give us some very direct clues about atmospheric pressure and the potential for good or bad weather.

Smoke rising

Rising smoke indicates a high-pressure area in the vicinity. High pressure is associated with fair weather and clear skies.

Smoke collapsing

When smoke collapses and curls， its indicative of a low-pressure system in the area. Indoors， the unexpected presence of wood smoke is another sign. Low pressure is associated with stormy weather.

Reading the sky

Red Sky at Night… is NOT a sailors delight！ This old adage is scientifically incorrect. The rotation of the Earth causes prevailing winds1 to come from the West. The sun sets in the West and a red sky indicates a significant cloud bank. Heavy clouds coming from the West with the prevailing winds is not a promise of delightful weather but the opposite.

Red Sky in Morning… is when sailors neednt take warning. Here again， the sun rises in the East and a red sky is due to cloud coverage. Those big clouds are receding from your location as the westerly prevailing winds carry them away from you.

Sun halos and moon halos

A ring around the sun or moon is referred to as a “Sun or Moon Halo.” Haloes are caused by high altitude ice-crystals in Cirrus clouds2. Because Cirrus clouds are a signal for impending rain， a ring around the moon usually means a warm front is coming， bringing rain with it. The same is true of sun haloes.

Reading rainbows

A rainbow in the western sky in the morning indicates rain. Here again， prevailing westerly winds will bring that moisture towards your location. The opposite is true for a rainbow in the East. The prevailing winds will move the moisture and rain away from you.

Reading the moon

A clear moon in a clear sky indicates no imminent3 moisture but could be a harbinger of cooler temperatures overnight and into the morning.

Scattered clouds across the Moon are a sign of moisture-laden clouds and often are a portent of rain.

Reading the flowers

Humidity strengthens smells in the air and fragrant flowers will be very noticeable as a result.

Wind

Wind is the result of high and low-pressure shifts in an area. As a rule， westerly winds indicate good weather if no clouds are apparent and easterly winds are an indication of bad weather. If youve ever heard of a NorEaster4， its due to this east wind condition.

Reading temperature

The cricket trick

A crickets metabolism changes in lockstep with5 temperature changes. Count the number of times a cricket chirps in 14 seconds and add 40 to that number. The resulting number approximates the temperature in Fahrenheit.

Reading the clouds

Reading cloud shape

Clouds that are high， white， and wispy indicate good weather while clouds that are low， thick， and dark mean stormy weather. Flat clouds mean the air is stable while fluffy clouds mean the air is unstable.

Reading cloud color

Clouds come in four flavors： white， gray， black， and brown. Each means something different.

Black clouds indicate a coming storm that does not have strong winds.

Brown clouds indicate a coming storm that has strong winds.

White clouds mean good weather， though a storm could be imminent.

Gray clouds indicate a new or a light storm. Gray skies can also mean that the storm is affecting a large area and may remain.

Reading altitude

High clouds usually mean that they are farther away but could become a weather threat up to 36 hours later. Lower clouds mean that bad weather is coming.

Movement

Gathering low clouds are a sign of bad weather. Rising and spreading clouds indicate the weather is clearing.

Reading the animals

Animals are very much in tune with nature and their instincts and response to conditions are a good indicator of weather to come.

Birds

Birds can sense air pressure patterns.

If you see birds eating during a storm， then it will likely last.

If you see flocks of birds migrating in the sky， the weather will likely be good.

When a storm is approaching， its believed that birds fly lower in the sky.

Frogs

The louder the frogs sing， the stronger the rain.

Turtles

Turtles head to higher ground before a storm. You may also see them on the road a day or two before a rain.

Snakes

If you see a snake in an unexpected place or time when the snake would typically be in its nest， bad weather is coming.

Butterflies and Bees

If you dont see bees and butterflies when and where you would expect to see them， there could be a storm coming.

Ants

Ants build up their mounds6 and create steep sides if theres a storm coming.

我們開疆拓土的先祖和土著部落居民早就會(huì)根據(jù)大自然中的跡象來(lái)預(yù)報(bào)天氣，那會(huì)兒離天氣頻道的出現(xiàn)還早得很。他們主要看的是天空，但天空、空氣和大氣壓對(duì)植物、動(dòng)物與人類的影響也能表露天象。

久而久之，形成了一些簡(jiǎn)明易懂的說(shuō)法，提醒我們天氣會(huì)如何變化，盡管從科學(xué)的角度看，其中部分說(shuō)法并不是那么準(zhǔn)確。

有關(guān)天氣的民諺：

晚霞水手喜，朝霞水手憂。

溝渠水臭，風(fēng)雨臨頭。

煙囪冒煙往下走，晴好天氣到了頭。

日暈月暈，雨雪將臨。

晨起有虹，如聞警鐘。

記住一些舊時(shí)諺語(yǔ)是個(gè)辦法，但如果能弄明白它們背后的科學(xué)原理，就會(huì)好記一些。

觀煙

燃燒產(chǎn)生的煙能以十分直觀的方式，提供關(guān)于氣壓和天氣趨勢(shì)的信息。

煙氣上升

煙氣上升，說(shuō)明附近地區(qū)處于高氣壓區(qū)。高氣壓意味著天氣晴好、天空明凈。

煙氣下沉

如果煙氣下沉、卷曲，說(shuō)明該地存在一個(gè)低壓系統(tǒng)。室內(nèi)突然聞到木柴燃燒的煙味，也是存在低壓系統(tǒng)的信號(hào)。低氣壓會(huì)帶來(lái)風(fēng)暴。

觀天

看到晚霞，水手可不會(huì)高興！這條古老的諺語(yǔ)不符合科學(xué)事實(shí)。地球自轉(zhuǎn)使西風(fēng)成為盛行風(fēng)。太陽(yáng)從西邊落下，紅彤彤的天空說(shuō)明空中云量豐富。從西邊順著盛行風(fēng)飄來(lái)的大量云朵并不會(huì)帶來(lái)讓人開心的好天氣，情況恰恰相反。

而如果出現(xiàn)了朝霞，水手并不需要有所警覺(jué)。和上面說(shuō)的例子一樣，太陽(yáng)從東邊升起，東邊天空紅彤彤是因?yàn)槟抢镌屏控S富。那些大塊的云朵正在離你遠(yuǎn)去，是因?yàn)槭⑿形黠L(fēng)正在將它們推向離你更遠(yuǎn)的地方。

日暈和月暈

太陽(yáng)或月亮周圍出現(xiàn)的環(huán)被稱為“日暈”或“月暈”。出現(xiàn)“暈”是因?yàn)楦吆０蔚木碓浦杏斜?。由于卷云預(yù)示著很快要下雨，月亮周圍出現(xiàn)光環(huán)通常說(shuō)明攜帶雨水的暖鋒即將過(guò)境。日暈的情況也一樣。

觀彩虹

早晨在西邊的天空看到彩虹，說(shuō)明要下雨了。與上面的例子同理，盛行西風(fēng)會(huì)把西邊的水汽向你所在的位置輸送。如果東邊出現(xiàn)彩虹，情況就正好相反。盛行風(fēng)會(huì)推動(dòng)水汽和雨離你遠(yuǎn)去。

觀月

如果天空明凈、月亮看得很清楚，說(shuō)明空氣中濕度不會(huì)太高，但這也可能預(yù)示著當(dāng)天夜間到次日清晨將要降溫。

如果疏落的云朵遮住了月亮，說(shuō)明云中水汽已飽和，這通常是降雨的前兆。

觀花

濕度升高后，空氣中的味道會(huì)更強(qiáng)烈，花朵的芬芳也會(huì)十分明顯。

風(fēng)

風(fēng)是某一地區(qū)氣壓高低變化的結(jié)果。一般來(lái)說(shuō)，如果刮西風(fēng)，又看不到多少云，說(shuō)明會(huì)有好天氣，而刮東風(fēng)則意味著天氣不好。你也許聽說(shuō)過(guò)“東北風(fēng)暴”，它也源自這種刮東風(fēng)的狀況。

觀測(cè)氣溫

借蟋蟀察氣溫

蟋蟀的新陳代謝與溫度的變化有十分緊密的聯(lián)系。數(shù)一數(shù)蟋蟀14秒以內(nèi)鳴叫的次數(shù)，再加上40，差不多就是當(dāng)前的華氏溫度。

觀云

觀云形

如果云位置較高、顏色雪白、如絲如縷，說(shuō)明接下來(lái)天氣晴好;如果云位置較低、厚重、陰沉，說(shuō)明暴風(fēng)雨將要來(lái)臨。云朵扁平，說(shuō)明大氣比較穩(wěn)定，云朵蓬松，則說(shuō)明大氣不怎么穩(wěn)定。

觀云色

云朵可能有四種顏色：白色、灰色、黑色和棕色，每一種都預(yù)示著不同的天氣狀況。

黑色云說(shuō)明暴雨即將來(lái)臨，但不會(huì)有大風(fēng)。

棕色云說(shuō)明要有暴風(fēng)雨，會(huì)刮強(qiáng)風(fēng)。

白色云說(shuō)明天氣不錯(cuò)，不過(guò)也可能有一場(chǎng)暴雨正在迫近。

灰色云說(shuō)明有一場(chǎng)新的風(fēng)暴正在醞釀，或者風(fēng)雨不強(qiáng)。天空呈灰色還可能意味著風(fēng)雨影響范圍很大，并有可能持續(xù)。

觀云高

一般來(lái)說(shuō)，海拔較高的云離得比較遠(yuǎn)。但到36個(gè)小時(shí)之后，天氣也有可能會(huì)轉(zhuǎn)差。云所處的海拔較低，意味著壞天氣就要來(lái)了。

觀云動(dòng)

如果云在低處不斷積聚，說(shuō)明會(huì)有壞天氣。云上升、散開，說(shuō)明天氣正在轉(zhuǎn)晴。

觀察動(dòng)物

動(dòng)物始終與大自然步調(diào)一致，了解它們的本能，觀察它們對(duì)環(huán)境狀況的反應(yīng)，對(duì)預(yù)報(bào)天氣很有幫助。

鳥類

鳥類能感覺(jué)到氣壓的變化。

如果看見鳥兒在風(fēng)暴中吃東西，那這場(chǎng)風(fēng)暴很可能將持續(xù)。

如果看見一群又一群鳥兒飛過(guò)天空，通常會(huì)有好天氣。

如果暴風(fēng)雨將要來(lái)臨，一般來(lái)說(shuō)鳥兒會(huì)低飛。

青蛙

蛙鳴越響，降雨越強(qiáng)。

烏龜

暴風(fēng)雨之前，烏龜會(huì)往高處去。下雨之前一兩天，你也許會(huì)在馬路上看見它們。

蟒蛇

如果本該待在巢穴里的蟒蛇在某時(shí)某地意外出現(xiàn)，就要有壞天氣了。

蝴蝶與蜜蜂

如果本該在某時(shí)某地出現(xiàn)的蜜蜂和蝴蝶沒(méi)有現(xiàn)身，就該有壞天氣了。

螞蟻

如果暴風(fēng)雨即將到來(lái)，螞蟻會(huì)建起小土丘并在四周壘出陡坡。

（譯者為“《英語(yǔ)世界》杯”翻譯大賽獲獎(jiǎng)?wù)撸?/p>

1 prevailing wind盛行風(fēng)。地球南北半球的中緯地區(qū)為盛行西風(fēng)帶。

2 cirrus cloud卷云。? 3 imminent迫近的;即將來(lái)臨的。

4 生成于北大西洋的溫帶氣旋，主要影響美國(guó)東北部、加拿大東部沿海等北美東岸地區(qū)。? 5 in lockstep with步伐一致，形容有緊密的關(guān)聯(lián)。

6 mound土丘，小土墩。