Säänmallinnusta

Säänmallinnusta, often translated as weather modeling or meteorological modeling, refers to the use of mathematical models and computer simulations to predict future weather conditions. These models are based on the fundamental laws of physics that govern atmospheric processes, such as fluid dynamics, thermodynamics, and radiation.

The process begins with gathering current weather data from a variety of sources, including weather stations, satellites, weather balloons, and radar systems. This data represents the initial state of the atmosphere. This information is then fed into complex numerical models, which divide the atmosphere into a three-dimensional grid. The models calculate how atmospheric variables like temperature, pressure, humidity, and wind will change over time at each point in the grid.

Different types of models exist, varying in their resolution (the size of the grid cells) and the complexity of the physical processes they represent. Global models cover the entire Earth, while regional models focus on specific geographical areas. Numerical weather prediction (NWP) models are the most common type, and their output is used by meteorologists to forecast weather for hours, days, and even weeks ahead. The accuracy of these models has steadily improved over the decades due to advancements in computing power, data assimilation techniques, and a deeper understanding of atmospheric science. However, weather remains a chaotic system, and perfect prediction is not achievable, with forecast accuracy generally decreasing with longer time horizons.