by ZAMG and KNMI

Common Remarks

The mature stage of Cold Air Developments are represented by a distinct cloud spiral but without any Warm Front cloudiness, this is the main difference to the classical Occlusion types (see also Occlusion: Warm Conveyor Belt Type and Occlusion: Cold Conveyor Belt Type ) and is caused by a completely different development. While the classical Occlusion types are frontal developments, is the initial stage a non-frontal Comma cloud in the cold air (see Comma ).

In connection with Commas the development of Polar Lows are a common phenomena especially in high latitudes. But the conceptual model Polar Low differs from the conceptual model Cold Air Development as in the Polar Low situation the low with a mesoscale Comma develops, while in the Cold Air Development situation frontal conditions develop leading to an increase of the scale of the cloud spiral.