云里有水，为什么不会整团掉下来？

Clouds are composed of tiny liquid water droplets, whose diameters are about the width of a human hair, and tiny shards of ice in a variety of shapes, or habits.

只使用液滴和冰晶组成的事实；不沿用头发宽度类比作定量尺寸依据。

These droplets feel the downward directed force of gravity just like a baseball or a watermelon would. Because the droplets are so small, and therefore have small masses, the gravitational force can easily be balanced by an upward directed friction force resulting from the interaction of the droplets with the air molecules around them and so the droplets remain suspended.

原文是科普简化；不把受力平衡写成液滴相对地面绝对静止，不采用同段过冷水温度举例。

the air parcels within the cloud are buoyant and literally bubble to the top.

仅用于部分对流云中存在上升运动；不得推广为所有云总是比周围空气轻或都有同样强的上升气流。

These droplets feel the downward directed force of gravity just like a baseball or a watermelon would. Because the droplets are so small, and therefore have small masses, the gravitational force can easily be balanced by an upward directed friction force resulting from the interaction of the droplets with the air molecules around them and so the droplets remain suspended.

原文是科普简化；不把受力平衡写成液滴相对地面绝对静止，不采用同段过冷水温度举例。

cloud droplets of varying size, with their different fall speeds, collide and stick together (coalesce), forming larger drops. Eventually, the drops become too large to be suspended in the air, and they fall to the ground as rain.

暖雨碰并过程；不推为所有降水只由液滴碰并产生。

The other process is the ice crystal process. This occurs in colder clouds when both ice crystals and water droplets are present. Water vapor more easily deposits directly onto ice crystals rather than coalesces as liquid drops, so the ice crystals grow at the expense of the water droplets. The crystals eventually become heavy enough to fall.

仅概述冷云冰相增长，不提供降水相态预报或固定成雨阈值。