Formation of mid-level clouds due to the approach of a North African low pressure system combined with a warm front passing at mid-levels of the atmosphere. The sun is only partially masked hence the cloud cover was As translucidus. However, in the background the cloud took more of a turbulent shape. Such sub-species is actually pannus (ie: As pannus). In this case, the altostratus pannus was formed as the warmer and more moist air in the warm front was forced slowly upwards and thus cooling in the process leading to this formation.