A parcel will continue to move away from its starting point with time resulting in an instability. In this instance the ambient anticyclonic horizontal wind shear is greater than the coriolis parameter. A necessary condition for an instability is that M decreases in the x-direction along parcel motion. The preceding analysis assumed that parcel motions are purely horizontal. Usually, parcels do not move horizontally.
Saturated parcels rise along pseudo-adiabats.
If the cross sections are not properly constructed, they can provide erroneous results. Horizontal anticyclonic wind shear. For example, the anticyclonic side of a strong jet streak can cause substantial shear along parcel paths. The 11 October 1997 is a good example of this situation. Vertical wind shear.