Deformation zone

[ckmc]

Hi there.

Can anyone explain to me what a "deformation zone"is in the context of mid-latitude cyclonic storms? I am thinking the recent nor'easter which was a great online case study to watch and learn.

A nice conceptual explanation in simple terms would be appreciated, explaining what these zones are, why they're found where they are found, and why they frequently lead to extended periods of snow after a low pressure system has already passed (i.e. just what is the mechanism which is producing the lift which causes the precipitation to form).

 

[oldseadog]

I hope I can answer it to your satisfaction.

First off, I will say that deformation zones are patterns primarily found in the upper levels of the atmosphere. So think 500 mb, about 5 km off the surface.

Anyway, the air flow at the upper levels can be pictured kind of like a river of air. But that river is always being pulled or pushed in different directions. So imagine a somewhat typical pattern of airflow at that level, from south to north. At the northern tip of this airflow, the pattern splits so some of the air goes east and some goes west. Picture what happens to the airflow in the middle. It gets torn apart and kind of mashed out, or deformed. The area where this happens is called a deformation zone.

 

[blizzard]

Thanks for the question. It is also something I was curius about.