ARPSView Guide

Understanding the Skew-T Diagram


Vertical profiles of temperature and dewpoint are plotted. ascent is also plotted. A sounding created from the background field (e.g., Eta) is sometimes plotted for diagnostic purposes.

The vertical profile of a parcel lifted pseudoadiabatically from the surface is sometimes shown as a dashed or dotted line. The upper-right corner contains the LCL (lifted condensation level) and LNB (level of neutral buoyancy) heights in millibars and kilometers, and the values of CAPE and CIN (J/kg). By looking at the parcel ascent profile, the overall stability and the positive and negative areas can be quickly determined. The temperature and dewpoint profiles themselves are useful for determining individual layer stability and the location of cloud layers.

Wind Profile

To the right of the Skew-T is the vertical wind profile with barbs indicating wind direction and the speed in knots. The height scale is in hundreds of feet MSL. This can be used to estimate winds aloft and is a useful diagnostic tool for severe weater. Severe storms, particularly supercells, require a vertical wind profile that has both strong veering and increasing speed with height.


The upper-left corner of the Skew-T contains a hodograph. The plotted curve connects the heads of the wind vectors at different altitudes in polar coordinates. Speeds are in meters/second and the altitude of selected points is given in kilometers MSL. The vertical shear vector is tangent to the hodograph curve. Storm relative helicity is proportional to the area of a sector defined by the 0 km wind, the 3 km wind, and the storm motion. The hodograph is useful in determining storm type and the potential for rotation.

Maintained by Kevin W. Thomas. Your comments, inquiries, problem reports, and suggestions are welcome.