What Will the Weather Be

What Will the Weather Be

天气会怎样

The sky was gray and cloudy over Washington, D. C. , on the morning of March 9, 1999. The weather forecast called for an inch or two of snow.

1999年3月9日上午，华盛顿特区的天空灰蒙蒙的，多云。天气预报说会下一两英寸的雪。

But by noon, there was so much snow on the ground that many cars and buses were stuck in it. The airports had to close down. So did the schools. In all, eight inches of snow fell on the city. The weather forecast was wrong. And people were not prepared for the huge storm.

但是到了中午，地上的雪太多了，许多汽车和公共汽车被困在里面。机场不得不关闭。学校也是如此。这座城市总共降下了8英寸的雪。 天气预报错了。人们对这场巨大的风暴没有做好准备。

Weather forecasts tell us what kind of weather is coming. But predicting the weather is hard to do. It is easy to see what the weather is like right now. You can go outside and look. Is the air warm or cold? Is it windy or still? Is the sky clear? Or is it covered with dark clouds? Whatever the weather is like, it often stays that way for days at a time.

天气预报告诉我们将要发生什么样的天气。 但是预测天气很难做到。 很容易看出现在的天气情况。 你可以出去看看。空气是热的还是冷的? 刮风还是无风?天空晴朗吗? 还是乌云密布? 无论天气如何，这种天气通常会持续好几天。

But then something happens. The wind begins to blow. Air from somewhere else moves in. Sometimes it is cooler air from the north. Sometimes it is warmer air from the south. The new air pushes against the old air. The place where this happens is called a front. Most changes in the weather occur along fronts.

但随后发生了一些事情。 风开始起了。空气从其他地方进入。 有时是来自北方的冷空气。 有时是来自南方的温暖空气。 新空气推动旧空气。 发生这种情况的地方被称为前线。 天气的大部分变化都发生在锋面上。

Where cold air pushes against warm air, we say there is a cold front. Cold fronts move fast. They can make the wind howl. They quickly push warm air up and out of the way. The rising air carries water. The water is not a liquid. It is a gas called water vapor. As the air rises, it cools, and the water vapor turns to liquid. High in the sky, the drops of liquid water clump together and make clouds.

当冷空气推动暖空气时，我们说有冷锋。 冷锋移动迅速。它们能使风怒吼。 它们迅速将热空气推高并移开。 上升的空气携带着水。水不是液体。 它是一种叫做水蒸气的气体。 当空气上升时，它会冷却，水蒸气变成液体。 在高高的天空中，液态水的水滴聚集在一起形成了云。