In particular, the case studied in this web presentation examines the QG-reasons for the ascent associated with the cloud and precipitation development in the area of an occluded wave cyclone normally referred to as "the overrunning area", "the warm frontal slope", and, most properly, the "warm advection area." This is the region on the cold air side of the surface warm front.

Specifically we seek to answer the question "...why does it frequently seem that precipitation north of the warm front is not uniform, and may be found in isolated sub-synoptic areas well "inside the cold air" region north of the warm front?

Of course, you can already take some good guesses. Since this area is also in the region of warm advection, one might suspect that the temperature advection forcing term in the QG-omega equation might explain that. That is to say, if the precipitation and cloud development is also coincident with, at a given level like 850 mb, a maximum in the warm advection field, then the temperature advection forcing term would be diagnosing ascent in the same region. By doing this, we of course are ignoring the impact of the differential vorticity advection field on the QG forcing.

The case studied here is a good illustration how a more sophisticated understanding of QG effects allows a comparable more sophisticated view on the vertical motion fields associated with cyclones. Since the two simplifications of the QG-omega equation combines the two forcing terms,

Case Study: A Mature Warm Front Occlusion in the Southeast, 00UTC 14 March 1999

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