yläilmakartat

Yläilmakartat, also known as upper-air charts or prognostic charts, are meteorological maps that display atmospheric conditions at specific altitudes above the Earth's surface. These charts are crucial tools for meteorologists to understand and forecast weather patterns. They typically show variables such as temperature, humidity, wind speed and direction, and pressure at different pressure levels, commonly 850 millibars (mb), 700 mb, 500 mb, and 300 mb. These pressure levels correspond to approximate altitudes.

The 850 mb level, for instance, is typically found around 1500 meters above sea level and is useful for tracking warm and cold air advection and low-level moisture. The 500 mb level, around 5500 meters, is particularly important as it often represents the mid-troposphere where significant weather systems, such as troughs and ridges in the jet stream, are clearly visible and can indicate areas of developing storms or clearing skies. The 300 mb level, near 9000 meters, is close to the tropopause and helps in analyzing the jet stream's position and strength, which greatly influences surface weather.

Yläilmakartat are generated using complex numerical weather prediction models that simulate the atmosphere's behavior. These models ingest vast amounts of observational data from weather balloons, satellites, aircraft, and ground stations to create initial conditions. The output of these models is then visualized in the form of yläilmakartat, allowing forecasters to analyze the three-dimensional structure of the atmosphere and make more accurate predictions about future weather events. They are indispensable for forecasting precipitation, storm development, and temperature changes over various time scales.