Thermal Front Parameter + Rel. Topography

Relative high values of the thermal front parameter can be found at the leading edge of the cold front as well as in wide parts of the frontal clouds. The cellular clouds in the cold air masses behind the front coincided with a trough of relative topography (700/1000 hPa).

Higher values of TFP indicate an intensification of the cold front. The development of the comma cloud took place east of the thickness trough's axis.

The cold front continued intensifying. The onset of the thickness gradient is clearly related to the approaching cold air in the rear of the cold front. The maximum values of TFP indicate the position of the cold front.

A few hours before the merging process, values of TFP were still high. The development took place in front of the thickness trough's axis.

After the merging the typical appearance of an occlusion spiral can be seen. The TFP weakens from this time on.

In the mature stage of the instant occlusion TFP and equivalent thickness reveal a ridge in the former comma area.

In the mature stage of the instant occlusion TFP and equivalent thickness exhibit a ridge in the former comma area.

Although the cloud band started decaying we still see high TFP and a ridge of relative topography near the eastcoast of England.

We still see the ridge in the relative tpography near the clouds of the instant occlusion. However, no relevant TFP values reveal in this region.