Cross-section F

Maximum of upward motion is located in the lower layers in the region just ahead the ground front. It is nicely correlated to the highest pixel values. Downward motion occurs behind the frontal zone.

Jet streak is found at about 250 hPa in the region of the highest pixel values, located just above the zone of high gradient of backward inclined isentropes.

There is strong positive vorticity behind the front. Note that the maximum coincides with the tropopause folding in the upper left corner of the cross-section.

Cold advection preveals in the entire cross-section and is very pronounced in the upper troposphere indicating the intrusion of cold air behind the front. The maximum of cold advection coincides also with the tropopause folding.

Positive vorticity advection is found to the right of the highest pixel values, above the frontal zone. Note how this vorticity advection maximum is correlated to the jet streak.