Stability of the environment

  • To determine the environmental stability, one must calculate the lapse rate for a sounding
  • lapse rate = DT/DZ = T2-T1/Z2-Z1
  • Since the environment is often composed of layers with different stabilities, it is useful to first identify these layers and then calculate their respective lapse rates
  • recall the stability criteria:
    • Ge < Gm - Absolutely stable
    • Gm < Ge < Gd - Conditional Instability
    • Gm < Gd < Ge - Absolutely unstable
  • Characterize the stability of the layers in the sounding to the right -->


Pull up the latest ALB sounding. Find the location of one absolutely stable, conditionally unstable, and absolutely unstable layer. Indicate the pressure of the base and top of these layers.