Frontogenesis

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551 Frontogenesis
Three main frontogenetical areas
in a typical developing cyclone
• Deformation frontogenesis with cold front
• Deformation (confluence)frontogenesis with
warm front
• Convergence frontogenesis near low center
(generally on portion of warm front closest to
the low center)
Using Garp software
Numerical Simulation of the Dec.
14-16, 1987 event
• Mass and Shultz, 1993
• Shultz and Mass, 1993
• Monthly Weather Review
Note fracture in frontogenesis along northern portion of CF
Important issue
we will discuss
in depth:
Frontogenesis
generally
accompanies
cyclogenesis
Surface-based fronts typically weaken
with height
How do we explain this?
Classic Paper That First Applied
Frontogenesis Diagnosis 3D for a
real case: Sanders 1955
Surface-based
Fronts Weakening With Height
• Rising motion and adiabatic cooling on warm
side.
• Sinking and adiabatic warming on on cold
side.
• Vertical motions increase with
height…therefore vertical motions increasingly
work against frontogenesis with height.
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