

Rain can be a blessing or a bane

As I write this column, it is raining outside my home office in Mountain City. For the last two or three days rain has fallen in various degrees. Sometimes the rain is a downpour, sometimes its a slow drizzle. Rain is welcomed by most folks in most times except when too much rain causes flooding. Flooding, of course, claims many lives and a great deal of property damage. On the other side of the coin, some folks have too little rain. I understand from news reports that California is in desperate need of water and more than likely rain would be welcomed especially by the farmers and homeowners of that state.
Sometimes thunderstorms strike and cause a great deal of damage, either by powerful straight-line winds or by lightning that accompany such storms. A large amount of rain in a very short time is often called a cloudburst.
Although I was a small child, I remember hearing about the cloudburst that occurred on August 13, 1940 that washed the railroad tracks away dooming the railroad service Mountain City had earlier.
The concept of rain seems simple enough. But sometimes things are a lot more completed than they appear. Such it is with rain. In my catching up about rain, I found that raindrops arent teardrop shaped as we often see them depicted. They appear as a hamburger bun as viewed from the top with a flat bottom and a rounded top.
In a perusal of one of my encyclopedias I found a good definition of rain.
The surface waters of the earth are constantly evaporating, changing into water vapor that mixes with air and is carried high into the atmosphere by winds and air currents. The temperature and pressure of the atmosphere decrease with altitude, so the air cools as it rises. Eventually, this cooling causes the water vapor in the air to condense. As it condenses, tiny droplets of water form around tiny airborne particles of matter called condensation nuclei, which include dust, solid particles in smoke, tiny crystals of sea salt, and volcanic ash.
Clouds are collections of enormous numbers of tiny water droplets. The droplets are so small and light that rising currents of air often keep many of them aloft. When small droplets fall toward the surface of the earth, many of them evaporate before they can reach the ground. The droplets that remain suspended in the atmosphere because of air currents grow larger and heavier as a result of coalescence.
This is a process in which water droplets collide with one another and in the process form larger droplets. When enough water droplets form and grow too heavy for rising air currents to keep them aloft, they fall to the ground as rain. The falling droplets of rain often collide with each other as well to form even larger raindrops.
Simple eh! It isnt really. It is interesting to know that each raindrop has a nucleus of foreign matter. A normal amount of rain is a boon but too much can be a disaster.