Foehn wind or Katabatic wind In the articles on Santa Ana winds it is made clear that this phenomenon is not constitute Foehn winds but are katabatic winds as their hot dry character is not due to flowing across mountain ranges and consequently losing moisture on the ascent but rather as a result of mechanical compression of subsident air as it descends from the interior plateau I would argue that at least some if not most berg wind events are caused by outflow of air from the interior plateau where the Kalahari High dominates during winter However at times berg winds may result from moist air ascending the Drakensberg or other eastern mountain ranges as it is advected onshore by a ridging South Indian or South Atlantic High and then subsequently descending the western escarpment devoid of moisture causing occasional searing mid and late summer heat along the western coastal belt in towns such as Paarl Wellington Vredendal Clanwilliam and Vioolsdrif