Its rare that you get an evolution so perfect as this. I invite you to step through the NASA GEO5 model and watch the life and death of extratropical cyclone Christina.

http://modeles.meteociel.fr/modeles/geos/runs/2014010300/geosnh-2-3.png?03-12

3h, the storm is adolescant, with the jet stream riding well to its north. It is still just about connected by an umbilical cold front to its parent which currently resides over the UK. Christina, does have a defined warm and cold front though the shape of the upside down V is gentle. Despite this she represents a strong devide between a tropical and polar airmass.

http://modeles.meteociel.fr/modeles/geos/runs/2014010300/geosnh-2-12.png?03-12

By 12h Christina has already reached 'frontal maturity' She now has a triple point with a slight indication of a warm occlusion. Her warm front is now particularly well defined and the warm sector has shrunk somewhat.

http://modeles.meteociel.fr/modeles/geos/runs/2014010300/geosnh-2-48.png?03-12

In terms of surface pressure Christina is in her prime by 48h, but frontally she is already showing signs of ageing. She has a well defined occlusion which is now bending back towards her in a classic anticlockwise spiral. Her cold front is starting to trail, indicating she may soon have offspring of her own. The triple point is very clearly visible and shows she is still a very energetic depression. From here on in though, she will start to age and decline.

http://modeles.meteociel.fr/modeles/geos/runs/2014010300/geosnh-2-72.png?03-12

By 72hr her centre lies undeneeth a 500mb low, indicating she will inevitably fill now. Her cold front trails the whole atlantic and ends in her daughter low which sadly will be quickly devoured by a nearby depression. Her warm front is nearly extinct indicating she is definately middle aged and will soon be elderly. The occlusion spiral completes a full 360 degree turn now and will continue to be torn apart by an upper level low.

http://modeles.meteociel.fr/modeles/geos/runs/2014010300/geosnh-2-96.png?03-12

By 96hr A now elderly christine is on her death bed. The cold front is completely detached and little more than a shower street. Her occlusion has disintregrated into an area of showers slowly weakening in activity or ready to be absorbed by a polar feature. 

http://modeles.meteociel.fr/modeles/geos/runs/2014010300/geosnh-2-120.png?03-12

Unfortunately an extratropical cyclone is doomed to weaken and decay slowly. By 120h all that is left of Christine is a frontless low. She still has an impressive 980mb centre, and will either continue her final journey to end up in the arctic; or be absorbed by a more active feature.

I post this, because Christine is an unusually 'classical' depression undergoing the all too often seen, but all too rarely realised wave-> V -> triple point -> occlusion only 

evolution

Excellent post and a superb explanation 

Thanks!

Its suprising how rare these textbook evolutions are. This was a particularly nice one. I might put together a montage of satellite images of Christina when she has run her course.