Convective cloud features in typical synoptic environments: Enhancement of convection by PV
PV anomalies (stratospheric values of PV low down in the troposphere) are preferred areas for the development of Cbs and Mesoscale Convective Systems.
If stratospheric air is penetrating into the troposphere, a PV anomaly associated with a vorticity maximum will be observed. The reason for this is that the static stability in the troposphere is significantly lower than in the stratosphere. When a PV anomaly approaches an area of moist and potentially unstable air, strong convection is initiated and convection systems such as EC, Comma, Cb Clusters or Mesoscale Convective System can develop. Additionally decaying systems can intensify through this process. Locations favourable for these phenomena are in cold air to the rear of frontal cloud bands.