Convective Cloud Features In Typical Synoptic Environments: Fair Weather Conditions - Typical Appearance In Vertical Cross Sections

• Isentropes:
  In vertical cross sections from the ECMWF model the isentropes of equivalent potential temperature show a super adiabatic stratification in the mid levels of the troposphere in all stages of the life cycle of convection. This is clearly a good indicator for strong convection.
• Relative humidity:
  As convection appears near the boundary between moist and dry WV features, two indicators are of interest in vertical cross sections of the relative humidity:
  • the representation of the dry and moist zones in WV images
  • the development of the CBs
  The dry stripe is accompanied by a relative minimum of relative humidity. As soon as CBs develop, the WV and IR pixel values show distinct maxima associated with areas of convection. However, the corresponding humidity maxima are mostly small.

	19 June 2005/18.00 UTC - Meteosat 8 WV 6.2 image; position of vertical cross section indicated

Isentropes

	19 June 2005/18.00 UTC - Vertical cross section; black: isentropes (ThetaE), orange thin: IR pixel values, orange thick: WV pixel values

Relative humidity

	19 June 2005/18.00 UTC - Vertical cross section; black: isentropes (ThetaE), blue: relative humidity, orange thin: IR pixel values, orange thick: WV pixel values