Typical Appearance In Vertical Cross Sections

  • Isentropes:
    The typical downward inclined crowding zone with the Cold Front, potentially unstable stratification in the lower troposphere in the Comma area
  • PVA:
    Maxima in the frontal zone increasing with height, a weaker maximum in the comma area.
  • Divergence:
    In the frontal zone convergence on the lower and middle levels, divergence above. In the Comma area convergence on the low layers, divergence on the middle layers.
  • Omega:
    Upward motion in the frontal zone and in the Comma area in lower and middle troposphere.

12 January 2007/06.00 UTC - Meteosat IR image; position of vertical cross section indicated
15 January 2007/06.00 UTC - Vertical cross section; black: isentropes
15 January 2007/06.00 UTC - Vertical cross section; black: isentropes, green: positive vorticity advection
15 January 2007/06.00 UTC - Vertical cross section; black: isentropes, magenta thick: convergence, magenta thin: divergence
15 January 2007/06.00 UTC - Vertical cross section; black: isentropes, cyan: upward motion