Six PV banner missions were realized during the Special Observation Period (SOP) of the Mesoscale Alpine Programme (MAP) in Sept-Nov 1999. Four of these missions were carried out to document secondary PV banners along different sections of the Alps. As opposed to the primary PV banners which emanate from the end points of a mountain range, secondary PV banners comprise an interior of the mountain-range wake, and mark wind shearlines that originate from massifs and isolated peaks along the complex mountain-range ridgeline.

In this study we compare and contrast two secondary PV banner cases from MAP SOP. The IOP 8 case took place during an episode of deep south Foehn, with the examined portion of the wake located to the north of the Alps over Bavaria. The other, IOP 15-Bora, case took place during a strong Bora with the examined wake located downwind of the Dinaric Alps over the Adriatic. We examine similarities and difference of the wake and secondary PV banner structure as well as the origin of potential vorticity anomalies in these two cases using available aircraft data and high-resolution numerical simulation predictions by the Navy's COAMPS (Coupled Ocean/Atmosphere Modeling Prediction System) model.