What determines if it will rain? How do meteorologist forecast this?
In: 4
Let’s start with what clouds are.
Clouds are just a bunch of water vapor, all in one place. Rain is what happens when the little water droplets in those clouds collide with each other, get too big, and fall from the cloud.
Forecasting rain is therefore about a few things. How much water is in the air? This is known as humidity. If it’s super humid, there’s more water in the air, which makes rain more likely.
The second question is: will the water “leave” the air? This is known as condensation; you’ve experienced this if you’ve ever seen water droplets on the outside of a cold bottle of water. That’s just the air cooling down, which causes the water to go from vapor to liquid form.
The third major factor is: where is this air? As I’m sure you know, it gets colder the farther into the air you go. This means that water is more likely to condense the farther upwards it goes, making rain more likely.
Forecasting rain is about forecasting these factors. You can use things like humidity measures, how much air pressure there is (which determines how easy it is for air to get “upwards”), the general temperature in the area, and many other factors like this.
If you know these factors in all of the surrounding areas, you can figure out how they will change. A simple example of this would be if you were in a hot house and it’s freezing outside. You know (intuitively) that your hot air will gradually rush towards the cold air until your house is the same temperature as the outdoors. There are similar things happening with humidity, air pressure, etc. that can cause changes in the weather.
Latest Answers