Which paradigm is considered often depends on the author and the discussion emphasis at the time. However, for the most part, and when considering all but the boundary layer flows, the rotating updraft concept is typically assumed. The mesocyclone should not be viewed as a rotating updraft. 3.0 Extratropical Cyclone and Mesocyclone Structure. Structure of a developing extratropical cyclone.
Fronts use conventional symbols.
This type of analysis stresses not the large air masses but the smaller scale concentrated airflows that determine the cloud and precipitation and the structure and evolution of the cyclone. It is carried out within isentropic surfaces in a coordinate frame traveling with the weather system. Cold conveyer belt - air ahead of and beneath the warm front which, relative to the advancing system, flows rapidly rearward around the polward side of the low center. Dry Intrusion - a stream of air from the upper troposphere and lower stratosphere, which, after earlier decent, approaches the center of the cyclone as a well defined reascending dry flow with low q w . First, it must be stressed that it is not the intent here to infer dynamic similarity of the ETC and mesocyclone in the strict sense of the term.