Cold Advection	The transport of relatively cold air by the wind.
Curvature Vorticity	The component of the relative vorticity depending on the curvature of the streamlines.
Convergence	The contraction of a two-dimensional wind field (u,v). Negative divergence.
Divergence	The expansion of a two-dimensional wind field.
Height Contours at 1000, 500, ... hPa	Contour lines of geopotential height above mean sea-level.
Isotachs	Lines of equal wind speed.
Negative Vorticity Advection	The transport of absolute vorticity leading to less cyclonic/more anticyclonic vorticity.
Vertical Motion (Omega)	Vertical motion in terms of pressure.
(Isentropic) Potential Vorticity	Vorticity which a column of air between two adjacent isentropic surfaces would have if it were brought to an arbitrary "standard" latitude and then stretched or shrunk to an arbitrary "standard" thickness.
Positive Vorticity Advection	The transport of absolute vorticity leading to more cyclonic/less anticyclonic vorticity.
Showalter Index	The index of the likelihood of thunderstorm occurrence: obtained by finding the temperature which would be attained by ascent of the air from 850 to 500 hPa and subtracting this from the actual air temperature at 500 hPa. Thunderstorms become more likely when the index <+3.
Shear Vorticity	The component of the relative vorticity depending on the horizontal wind shear.
Temperature Advection	The transport of temperature by the wind.
Thermal Front Parameter	The change of temperature gradient in the direction of the temperature gradient.
(Equivalent) Thickness	The thickness of the atmospheric layer between two pressure surfaces.
Potential Temperature	The temperature that an unsaturated parcel of dry air would have if brought adiabatically and reversibly from its initial state to a standard pressure p0, typically 1000 hPa.
Equivalent Potential Temperature	Similar to Potential Temperature, but for moist air.
Vorticity Advection	The transport of absolute vorticity by the wind.
Vorticity	The rotation of a two-dimensional wind field (u,v).
Warm Advection	The transport of relative warm air by the wind.
Wet Bulb Temperature	The temperature an air parcel would have if cooled adiabatically to saturation and then compressed adiabatically to the original pressure in a moist adiabatic process.