COLD FRONT IN COLD ADVECTION - KEY PARAMETERS

by ZAMG


30 January 1999/06.00 UTC - Meteosat IR image; red dashed: temperature advection - CA 700 hPa, red solid: temperature advection - WA 700 hPa
30 January 1999/06.00 UTC - Meteosat IR image; blue: thermal front parameter, green: equivalent thickness
30 January 1999/06.00 UTC - Meteosat IR image; blue dashed: dry advection 700 hPa, blue solid: humid advection 700 hPa
This example shows dry advection throughout the whole area. Normally there is a change of sign at the frontal surface. If there is none, the front is likely to decay.

30 January 1999/06.00 UTC - Meteosat IR image; yellow dashed: vertical motion (omega) - upward motion 850 hPa, yellow solid: vertical motion (omega) - downward motion 850 hPa
Upwards motion is found in front and within the frontal cloud band. At the rear edge downward motion can be seen.
The image shows upward motion over a large area: only at the rear edge is there a small region where sinking is evident.

SUB-MENU OF COLD FRONT IN COLD ADVECTION
METEOROLOGICAL PHYSICAL BACKGROUND
TYPICAL APPEARANCE IN VERTICAL CROSS SECTIONS