SECONDARY LOW CENTRES IN OCCLUSION CLOUD BANDS - TYPICAL APPEARANCE IN VERTICAL CROSS SECTIONS
by FMI
- Isentropes
:
The structure of an Occlusion is seen in the isentropes. As the Occlusions can be fairly old, however, the v-shaped structure with warmer isentropes above may not always be as clear as in younger systems. - Divergence:
As in a typical deepening low, there is convergence at low levels and divergence at high levels over the secondary low. - Positive vorticity advection:
There is a maximum on PVA ahead of the developing low in the lower troposphere.
|
06 March 2002/00.00 UTC - Meteosat IR image; position of vertical cross section indicated
|
|
|
|
|
06 March 2002/00.00 UTC - Vertical cross section; black: isentropes (ThetaE), magenta thick: convergence, magenta thin: divergence,
orange thin: IR pixel values, orange thick: WV pixel values
|
|
|
|
|
06 March 2002/00.00 UTC - Vertical cross section; black: isentropes (ThetaE), green: positive vorticity advection (PVA), orange thin: IR
pixel values, orange thick: WV pixel values
|
|
|
|
