Cold Front

• Cloud Structure In Satellite Images
• Meteorological Physical Background
• Key Parameters
• Typical Appearance In Vertical Cross Sections
• Weather Events
• Special Investigation: Cold Front/Occlusion
• Special Investigation: Convective Weather Events Within Or At The Rear Of Frontal Cloud Bands
• References

Weather Events

Weather features are highly variable and can differ from season to season. Features are desribed here for two types of fronts: Ana and Kata Cold Fronts.

Ana Cold Front

Parameter	Description
Precipitation (incl. thunder)	Moderate to heavy showery precipitation Thunderstorms can occur in all seasons.
Temperature	Falls rapidly after the passage of the front. Over land in wintertime, temperatures can rise after the frontal passage.
Wind (incl. gusts)	Around embedded Cbs strong gusts are possible. Veering of the wind at the frontal passage.
Other relevant information	Precipitation in narrow cloud band just ahead of front (line convection) Enhanced areas with precipitation behind the surface front Risk of moderate to severe icing and turbulence. Severe weather generally occurs in regions with PVA superimposed, e.g. the left exit region of a jet streak

These features are best illustrated using data from 3 September 2019 at 12 UTC when an Ana Cold Front appeared over north-eastern Europe.

3 September 2019,12 UTC: IR image.

3 September 2019, 12 UTC: IR + synoptic measurements (above) + probability of moderate rain (Precipitting clouds PC - NWCSAF).
Note: for a larger SYNOP image click this link.

Precipitation in the form of showers is widespread, and several reports of Cbs can be seen. A comparison with the precipitation probability from the NWC SAF shows that the precipitation reports correspond to the areas with highest precipitation probability (ochre to red areas) south of about 60° N.

3 September 2019, 12 UTC, IR; superimposed:
1st row: Cloud Type (CT NWCSAF) (above) + Cloud Top Height (CTTH - NWCSAF) (below); 2nd row: Convective Rainfall Rate (CRR NWCSAF) (above) + Radar intensities from Opera radar system (below)

For identifying values for Cloud type (CT), Cloud type height (CTTH), precipitating clouds (PC), and Opera radar for any pixel in the images look into the legends. (link)

Kata Cold Front

Parameter	Description
Precipitation (incl. thunder)	Precipitation ahead of surface front Precipitation sometimes in narrow bands ahead of surface front Thunderstorms can occur in all seasons.
Temperature	Falls rapidly after the passage of the front. Temperatures can rise after frontal passage over land in wintertime.
Wind (incl. gusts)	Around embedded Cbs strong gusts are possible. Veering of the wind at the frontal passage
Other relevant information	Risk of moderate to severe icing Risk of moderate to severe turbulence

These features are best illustrated using data from 4 November 2019 at 12 UTC, where a Kata Cold Front Band extended from Greece northward across the Balkan Peninsula to Poland.

4 November 2019, 12 UTC, IR.

4 November 2019,12 UTC: IR + synoptic measurements (above) + probability of moderate rain (Precipitting clouds PC - NWCSAF).
Note: for a larger SYNOP image click this link.

Rain and shower observations are wide-spread. The shower reports appear more near the leading edge, while rain reports appear more near the rearward edge. The highest precipitation probabilities up to 100 %, are in the southernmost part of the kata cold front cloud band over northern Greece, the Peloponnese and further into the Mediterranean.

4 November 2019, 12 UTC, IR; superimposed:
1st row: Cloud Type (CT NWCSAF) (above) + Cloud Top Height (CTTH - NWCSAF) (below); 2nd row: Convective Rainfall Rate (CRR NWCSAF) (above) + Radar intensities from Opera radar system (below)

For identifying values for Cloud type (CT), Cloud type height (CTTH), precipitating clouds (PC), and Opera radar for any pixel in the images look into the legends. (link)