In lecture we learned that a parcel will rise if it is warmer than the environment and sink if it is cooler than the environment. We look at thermodynamic diagrams like skew-T’s to determine this. If the plotted temperature profile decreases more rapidly with height than the dry adiabatic lines or the moist adiabatic lines, we say the atmosphere is absolutely unstable. If the temperature profile decreases less rapidly with height than both dry and moist adiabatic rates, then the atmosphere is absolutely stable. If the temperature profile falls between the dry and moist rates, then it is conditionally unstable.

Look at the following diagrams and determine whether the profiles are absolutely stable, absolutely unstable, or conditionally unstable.

The attached sounding gives a temperature and dew point profile for a certain day. The dark line drawn shows the path of a parcel that is lifted from near the surface.

At what height (in mb of pressure) is the lifted condensation level?

At what height does the parcel become warmer than the environment (where is the level of free convection)?

Is there any positive area (CAPE) on this sounding?