SAVANNAH, Ga. (WTOC) - Raindrops. They come in many shapes and sizes. But, from a fine mist to those gigantic raindrops just before a downpour, what causes such a difference?
It all has to do with the processes behind how a storm forms. Let's think back to the water cycle.
And, of course, one of the most important parts of the when it comes to rain showers developing is the cooling and condensing of water vapor to form a cloud. A cloud is, basically, just a bunch of teeny-tiny little water droplets and those little tiny water droplets tend to bump into one-another.
They will merge and they will form bigger droplets and that process tends to repeat so that eventually rain will fall out of the clouds because the air, rising vertical winds, or the updraft that will send water droplets up into the cloud, it's not strong enough to hold the bigger drops anymore, depending on the strength of that wind. So, eventually, it will fall out of the cloud in the downdraft, make it all the way down to the surface and, of course, it could wet the lawns, cancel your BBQ plans and the such like that.
But, let's think about this, the stronger this vertical wind - the updraft - the more likely you are to have big raindrops, because along that journey the little tiny raindrops will bump into other raindrops which will allow it to grow larger and then bump into other raindrops which will allow it to grow even larger before finally becoming too heavy and falling out of that cloud.
So, if you tend to notice big raindrops on the pavement as rain starts that could be a strong shower, a very tall rain cloud able to produce very big raindrops.
The smaller raindrops are simply ones that didn't' have a chance to run into other drops and grow larger.
It is also more likely that a taller cloud, with a stronger updraft, is more likely to produce bigger rain drops as its updraft will be stronger – allowing raindrops to collide and grow bigger more often.
Next time it starts raining, try to see if the drops are big or small. Are there a few giant drops or many, many small drops?
What’s happening way up in the sky above your head will determine the answer.