Deformation Band - Key Parameters

• Wind vectors or streamlines at 300 and 500 hPa
  Wind vectors, preferably streamlines, show the presence of a col (saddle surface) at the area of deformation, with confluence on both sides of the col
• Total deformation at 300 and 500 hPa
  Total deformation maximum found in the vicinity of the col, with maximum values in the confluent zone on the cold side, where the jet is tightest
• Upper/middle tropospheric humidity
  High relative humidity gradient at the axis of dilation
• Omega at 700 hPa
  Weak or moderate sinking motion at, and on the cold side of the deformation zone

Wind/streamlines 300/500 hPa

	28 November 2004/06.00 UTC - Meteosat 8 IR 10.8 image; yellow: streamlines 300 hPa

Total deformation 300 hPa

	28 November 2004/06.00 UTC - Meteosat IR image; brown: total deformation 300 hPa

Humidity 500 hPa

	28 November 2004/06.00 UTC - Meteosat 8 WV 6.2 image; blue solid: relative humidity 500 hPa > 70%, blue dashed: relative humidity 500 hPa < 70%

Omega 700 hPa

	28 November 2004/06.00 UTC - Meteosat IR 8 10.8 image; yellow solid: sinking motion, yellow dashed: rising motion