Introduction to Weather Forecasting

What is Weather?

In order to explain a bit about weather forecasting, you need to know what "weather" means and we start start with a definition of the word "meteorology".

Meteorology is the study of Earth's atmospheric conditions. "Meteor" comes from the Greek word "Meteoron", which means "high in the sky". The "ology" part of the word means "the study of...". In this context, the study of high in the sky is the atmospheric conditions, which are high up.

Weather is the day-to-day meteorological condition of a certain place at a certain time measured in terms of wind, precipitation, clouds, atmospheric and ground level temperatures.

It is energy that drives our weather. The energy is transferred through the movement of air, which occurs as a result of temperature differences across different areas of our atmosphere. This is known as convection.

The Water Cycle

The basic principle of weather can be explained in terms of the water cycle. The sun heats our planet. The water in our seas and oceans start to rise and form water vapour as they start to heat up. This process is called evaporation. As the water vapour rises further into our atmosphere, it cools and starts to thicken. The water vapour eventually forms clouds and this is condensation. As more and more vapour condenses, the clouds get heavier and eventually cannot hold the water any longer. Water starts to fall from the clouds through our atmosphere in the form of rain, sleet, snow, hail, ice pellets, freezing rain etc (depending on temperatures at various levels of the atmosphere)

Measuring Weather Conditions

In order to forecast our weather, we must be able to measure the current conditions. Meteorology is a science that requires you to learn through past conditions and experiences so it is essential that we are able to take readings.

We need to measure: temperature, pressure, sunshine, rainfall, humidity and wind. We also need to be able to look out our window and see what is going on outside. The clouds can tell us a great deal about what is going on in our atmosphere. Each type of cloud produces different weather conditions (though some share similar characteristics). More detail about this will be covered soon.