“北京暴雨”持续刷屏，网友：比依萍借钱那天的雨还大？（北京暴雨强度公式最新）

前天，全北京人民都在等一场雨，皆因前一天收到的各种暴雨预警通报。

8月11日，北京市气象部门预报显示，京津冀地区于12日将有一次区域性强降雨天气过程，为今年入汛以来最强降雨过程。

北京市规划自然资源委和市气象局8月11日20时联合发布地质灾害气象风险黄色预警。未来48小时，北京市山区发生泥石流、崩塌、滑坡等地质灾害的风险较高，请注意防范。

（图源：微博@气象北京截图）

紧接着，北京市文化和旅游局发布提示，12日零时起北京市山区景区全部关闭。

8月12日北京市属11家公园临时关闭，包括颐和园、天坛公园等。

（图源：北京市公园管理中心官网）

不少企事业单位也通知在家办公，市民们还收到多条来自北京市防汛办减少外出的提醒。

（图源：北京市防汛办短信提示截图）

然鹅，12日一早，准备喜提暴雨的小伙伴们推开窗却发现——晴空万里，风和日丽！

What?! 是我拿错了剧本？

于是，所有人都开启了兼职求雨模式，硬是把等了大半天还没来的暴雨推上热搜。

（图源：微博话题热搜）

许多热心网友也在认真分析雨迟迟不来的原因↓

（图源：微博@最乖的大学生）

还有网友在等待中预测这波雨会有多大？

（图源：中国日报双语新闻公众号）

午后，北京城区的雨终于姗姗来迟，下大了天地朦胧一片，大雨倾盆如注！

到了晚间，暴雨犹如开挂了似的，酣畅淋漓地倾注下来。12日夜间，这场大雨终于圆满收官。

▲ 8月12日，北京，海淀区的市民夜晚冒雨出行。当日，北京夜迎强降雨。（图源：视觉中国）

那么，小伙伴们，你们知道各级预警用英语怎么说？从小雨到大雨又该如何表达？雨又是如何形成的呢？

各级预警

暴雨预警分为4个级别，分别是蓝色、黄色、橙色、红色，主要划分依据为特定时间段降水量。

BLUE:

In the next 12 hours, the rainfall will be up to above 50 mm,or is likely to continue with a basis of 50 mm.

十二小时内，降雨量达到50mm以上，或者已经达到50毫米以上且降雨可能持续。

YELLOW:

In the next 6 hours, the rainfall will be up to above 50 mm, or is likely to continue with a basis of 50 mm.

六小时内，降雨量达到50mm以上，或者已经达到50毫米以上且降雨可能持续。

ORANGE:

In the next 3 hours, the rainfall will be up to above 50 mm,or is likely to continue with a basis of 50 mm.

三小时内，降雨量达到50mm以上，或者已经达到50毫米以上且降雨可能持续。

RED:

In the next 3 hours, the rainfall will be up to above 100 mm,or is likely to continue with a basis of 100 mm. 三小时内，降雨量达到100mm以上，或者已经达到100毫米以上且降雨可能持续。

（图源：视觉中国）

雨的强度

Rainfall intensity is classified according to the rate of precipitation:

降水强度根据降水速率可分为以下几类：

• Light rain — when the precipitation rate is < 2.5 mm (0.098 in) per hour

小雨——降水速率小于2.5毫米（0.098英寸）每小时

• Moderate rain — when the precipitation rate is between 2.5 mm (0.098 in) – 7.6 mm (0.30 in) or 10 mm (0.39 in) per hour

中雨——降水速率介于2.5毫米（0.098英寸）至7.6毫米（0.30英寸）或10毫米（0.39英寸）每小时

• Heavy rain — when the precipitation rate is > 7.6 mm (0.30 in) per hour, or between 10 mm (0.39 in) and 50 mm (2.0 in) per hour

大雨——降水速率大于7.6毫米（0.3.英寸）每小时，或介于10毫米（0.39英寸）至50毫米（2.0英寸）每小时

• Violent rain — when the precipitation rate is > 50 mm (2.0 in) per hour

暴雨——降水速率大于50毫米（2.0英寸）每小时

（图源：视觉中国）

雨的类型

Rain falls when moist air rises and cools. Cooling air is condensed and thus produces rain as it transforms from a vapor into a liquid. Four distinct weather patterns produce rain–each creating their own kind of rain, with distinct cloud formations and varied properties. The four specific types of rain commonly are referred to as frontal, relief, convection and monsoon.

当潮湿的空气上升遇冷就形成了雨。冷空气凝结后，从水蒸汽转变为液体，于是就产生了雨。雨是由四种不同的天气类型而形成的，对于每种类型来说，云的形成和各种特性都有所不同。一般来说，雨可分为四个典型类型：锋面雨、地形雨、对流雨和季风雨。

WARM FRONT 暖锋

A frontal rain requires the meeting of two air masses. It includes two different transformations–one being warm air meeting cold; the other being the reverse. When the movement of warm air encounters a steady flow of cold air, it is called a warm front. Because they maintain different densities, the warm and cold air cannot mix. The heavier cold air slips underneath the warm air. As the warm air rise, it eventually cool, thus condensing to cause clouds and rain. A warm front requires ample time to produce precipitation as its system changes from one cloud type to another before finally generating rain. Warm fronts can occur at any time, day or night, can take place over land or sea and may last from mere hours to many days.

锋面雨是由两种气团相遇而产生的，包括两种不同的转换形式：一是暖气团遇到冷气团，二是冷气团遇到暖气团。当暖气团在移动的过程中遇到冷气团稳流，称为暖锋。由于暖气团和冷气团的密度不同，所以它们不会混成一体。较重的冷气团移至暖气团下方。暖气团在抬升的过程中最终冷却凝结，形成云和雨。暖锋需要足够的时间来形成降水，因为在形成雨水之前，暖锋系统的云型会发生变化。暖锋在白天或夜晚随时都有可能发生，可以发生在海洋，也可以是陆地上，持续时间可从几小时至数天。

COLD FRONT 冷锋

The pattern of a cold front is reversed–with the cold air coming along to meet the steady stream of warm air. With the cold air being the predominant mass, the air is forced up quickly causing the rapid and large creation of cumulonimbus clouds. This combination produces an intense rainfall usually associated with thunder, lightning, and sometimes hail. Just as swiftly as a cold front comes on, it can dissipate and give way to clear blue skies.

冷锋的模式和暖锋相反，是由冷气团遇到暖气团稳流而形成。冷气团在空气中起主导作用，使空气迅速抬升，快速形成大量积雨云。这种结合会产生暴雨，通常还伴有雷鸣、闪电，有时还有冰雹。冷锋来的快去得也快，速速给透明如洗的蓝天让路。

RELIEF 地形

Mountainous regions maintain the elements required for relief rains. This weather pattern occurs when steadily moving air suddenly is required to move upward to cross over an elevated obstruction. As the air rises in its effort to pass over a mountain, it begins to cool, creating moisture and clouds (in the form of either mist or rain) on the side of the mountain where the air is rising. After the air begins its descent down the other side, it warms and can no longer produce moisture. Many mountains portray this meteorological phenomenon with one side being lush and green, while the other is barren and dry.

山区包含形成地形雨的条件。当平稳移动的气流突然遇到高海拔障碍物，被迫抬升以越过阻隔时就会形成地形雨。气流翻越山脉的过程中开始冷却，在迎风坡形成湿气和云层（以云雾或降雨的形式）。随后气流开始在背风坡下沉并逐渐增温，不再形成湿气。在这种气象现象的影响下，很多山区呈现出一侧植被葱郁、另一侧干旱贫瘠的面貌。

CONVECTION 对流

A convection rain falls from the result of sunshine, air pressure and altitude–requiring warm ground and low pressure. Low pressure creates unstable air that rises as the sun warms the ground all day. By afternoon the moist air rises rapidly, creating large cumulonimbus clouds and sudden, sometimes torrential, downpours.

对流雨的形成需要阳光、气压和海拔三个条件，即温暖的大地和低气压。全天的日照使得地面升温，低气压造就的不稳定气流随之上升。午后时分潮湿气流迅速上升，形成大量积雨云，顷刻间大雨如注。

MONSOON 季风

Monsoons produce seasonal rainfall. They only occur in specific regions on Earth. During the dry season, the air moves steadily onto land from the ocean, where it descends and moves back out to sea. Continuing in this way, the air never rises and cannot produce moisture. The opposite holds true when monsoon season hits. Reversing its course as the land becomes warmer than the ocean, the air rises from the land, heads out to sea, descends and returns to land, rising again. This continued cycle generates copious amounts of rain with an intensity and duration that varies with every passing year.

季风带来季节性降水，只出现在地球上的特定区域。在旱季，大气从海洋流向陆地，在陆地形成下沉气流，然后回到海洋，如此往复循环，没有气流上升过程，不会形成湿气。季风时节到来时上述过程逆向进行，陆地的温度高于海洋，气流从陆地升起流向海洋，然后下沉回到陆地，再次上升。这个循环过程会带来丰富的降水，雨量和持续时间每年都会发生变化。

雨的词汇表达：

drizzle; fine / drizzling rain 细雨/毛毛雨

occasional drizzles 零星小雨

periodical / intermittent / recurrent rain 间歇雨

shower 阵雨

rapid rain 急雨

driving rain 猛烈的雨

heavy rain; downpour 大雨

heavy downpour; pouring / pelting rain 倾盆大雨

constant / continuous / incessant rain 连绵不断的雨

hail 冰雹

sleet; rain mixed up with hail 雨夹雹

yearly / annual precipitation 年降水量

rainfall / precipitation 降雨量

rainy season 雨季

rain belt 雨带，多雨地带

有关下雨的实用句型：

It is rainy today. 今天是下雨天。

It is going to rain. 要下雨了。

The rain drizzles down. / It drizzles/sprinkles. 下毛毛雨了。

It showers. 下阵雨了。

The rain falls heavily. 下大雨了。

It rained cats and dogs. 俚语，形容雨下得很大。

It’s really coming down out there. 那里雨下得很大。

We had a downpour. 我们遇到了一场倾盆大雨。

I am soaked. 我湿透了。（我被淋成落汤鸡了。）

来源：译.世界