Meteorologists do not promise the weather, but predict it, and this process is not divination, but a complex scientific work based on physics, mathematics, and enormous computing power. Here is how it happens step by step. Step 1: Collection of Data on Current State All starts with answering the question: “What is happening right now?”. Meteorologists collect data from all over the world and do this almost in real-time. Sources of information: Ground stations. Measure temperature, pressure, humidity, wind, and precipitation at the earth's surface. Satellites. Provide about 80% of all information about the current state of the atmosphere, especially over oceans and inaccessible areas. Radar. Track precipitation and dangerous phenomena at relatively low altitudes. Aerological balloons and aircraft. Measure parameters in the upper layers of the atmosphere. All these data undergo control: erroneous values are discarded, information is matched and absorbed to create the most accurate map of the initial state of the atmosphere. Step 2: Calculation on Supercomputers (Numerical Forecast) This is the heart of modern meteorology. The received data are loaded into a numerical weather prediction model — a complex software complex that solves a system of equations describing the physics of the atmosphere. The atmosphere is divided into millions of virtual cells (grid). The supercomputer calculates how temperature, pressure, and wind in each cell will change in a few seconds, then uses this result as a new starting point for the next step, and so day by day. That's why some of the most powerful computers in the world are needed to calculate the forecast. Step 3: Evaluation of Uncertainty (Ensemble Forecast) The atmosphere is a chaotic system. A tiny error in initial data can grow into a huge error in a few days. To account for this uncertainty, an ensemble forecast is used. Instead of one calc ... Read more