Mid-level clouds formation preceding a deep surface low pressure over Morocco due to cool oceanic air interecting with the Atlas mountains and being strongly heated at the surface. In fact the visible satellite image shows what looked like a front but the widespread of this cloudiness was more likely due to a strong jet stream of around 180kmh at its peak. It seemed that rain was falling from this cloud hence altocumulus virga. The virga was seemingly blown eastwards due to winds from a western quadrant at mid-levels. The first thumbnail shows altocumulus perlucidus formed on the same day in association with the same passing cloud wave as seen in the visible satellite image.