Skew-T plotting tool

Start the AIRS Skew-T plotting tool

User Guide

skewt example
Color Skew-T log-P diagram. In this image, red lines are isotherms, solid green lines are the potential temperature, and dashed green lines are the equivalent potential temperature; these three all use the temperature scale at the horizontal 1000 mb level near the bottom. The blue lines are the isobars (scale on the left side) and the dashed purple lines are the saturated humidity mixing ratio (scale inside the graph, near the right). Credit: Wikipedia

About Skew-T plots

The Skew-T plot, sometimes referred to as the Skew-T diagram or map, is a very useful meteorological thermodynamic chart on which pressure, density, temperature, and water vapor are plotted for a point on the Earth up through the atmosphere.

The Skew-T plot gives a "snapshot" picture of temperature, dewpoint, air pressure, and winds in the atmosphere above a particular point on the Earth's surface to a maximum of about 16 kilometers above sea level. It is a basic tool used in forecasting not only severe storms, but also daily weather. On the Skew-T plot, the "skewed" horizontal axis slants upward to the right hand side of the diagram at a 45 degree angle, and the temperature is usually in Celsius degrees; the vertical axis is atmospheric pressure in millibars. Atmospheric pressure decreases with altitude.

Every Skew-T plot consists of both a static set of atmospheric calculations, which apply equally to all locations, and a dynamic set of air temperature and dew point temperature calculations obtained by the lofting of a small radiosonde instrument package, commonly referred to as a weather balloon. NASA's Atmospheric Infrared Sounder (AIRS), with the help of its sister instrument, the Advanced Microwave Sounding Unit (AMSU), have been deriving these temperature and pressure profiles remotely from space since shortly after their May 4, 2002 launch aboard NASA's Earth-orbiting Aqua satellite.


This custom Skew-T tool designed to work with the AIRS data set enables you to browse weather data anywhere in the world (at least twice per day in most locations). It is NOT a research-grade software application, although the data which it reads are of this caliber. Please be aware that these data files contain substantial amounts of quality control and precision indicators that are essential to using the AIRS data in any serious scientific investigation. This Skew-T web application takes a conservative approach in converting these AIRS/AMSU observations in a Skew-T-appropriate data set. Therefore, for every six-minute period of time covering a particular ground track, a selected subset of the possible 1,350 individual observations may not be available. In addition, the algorithms that reconstruct the air temperature and water vapor profiles sometimes have difficulty over stretches of land or in the presence of very thick low-lying clouds.

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