Conditional Instability

• consider the diagram to the right, notice that at 2 km (or anywhere for that matter):

• T_up < T_e < T_sp

• The unsaturated parcel will be cooler than then environment and will sink back to the ground

• The saturated parcel will be warmer than the environment and will continue to ascend

• This is an example of conditional instability

• What is the condition???? ANSWER

  The condition for conditional instability is:

  • G_d>G_e>G_m

• G_d is the dry adiabatic lapse rate (10°C km^-1)
• G_e is the environmental lapse rate (7.8°C km^-1)
• G_m is the moist adiabatic lapse rate (6°C km^-1)