convective instability

The state of the atmosphere in which there is a high relative humidity at low levels and a low relative humidity at upper levels, such that if a low layer of air is lifted bodily, the ELR (environmental lapse rate) value through the layer will gradually increase until it attains an unstable value. ELR is the lapse rate in the surrounding air within which a volume of air is being lifted. DALR, or dry adiabatic lapse rate, and SALR, or saturated adiabatic lapse rate, are lapse rates of dry and saturated air masses, respectively, when they are lifted adiabatically. The values of DALR and SALR are 3°C and 1.5°C /1000 ft, respectively. This is often seen in cold fronts, where convective instability is the major cause of instability. Also known as potential instability.
A parcel of air is stable at A and B and becomes unstable at C indicating convective instability from C onwards.

Aviation dictionary. 2014.

Look at other dictionaries:

  • Convective instability — For a more general discussion of the same phenomenon, see Convective available potential energy. This article incorporates public domain text created by the US government. In meteorology, convective instability or stability of an airmass refers… …   Wikipedia

  • Convective available potential energy — A skew T plot showing a morning sounding with a large hydrolapse followed by an afternoon sounding showing the cooling which occurred in the mid levels resulting in an unstable atmosphere as surface parcels have now become negatively buoyant. The …   Wikipedia

  • Instability — [ Hydrodynamics simulation of the Rayleigh–Taylor instability [Shengtai Li, Hui Li Parallel AMR Code for Compressible MHD or HD Equations (Los Alamos National Laboratory) [http://math.lanl.gov/Research/Highlights/amrmhd.shtml] ] ] Instability in… …   Wikipedia

  • Convective inhibition — A Skew T diagram with important features labeled Convective inhibition (CIN or CINH) is a numerical measure in meteorology that indicates the amount of energy that will prevent an air parcel from rising from the surface to the level of free… …   Wikipedia

  • Convective condensation level — The convective condensation level (CCL) represents the height where an air parcel becomes saturated when lifted adiabatically to achieve buoyant ascent. It marks where cloud base begins when air is heated from below to the convective temperature …   Wikipedia

  • Convective temperature — The convective temperature (CT or Tc) is the approximate temperature that air near the surface must reach for cloud formation without mechanical lift. In such case, cloud base begins at the convective condensation level (CCL), whilst with… …   Wikipedia

  • Convective overturn — The convective overturn model of supernovae was proposed by Bethe and Wilson in 1985, and received a dramatic test with SN 1987A, and the detection of neutrinos from the explosion. The model is for type II supernovae, which take place in stars… …   Wikipedia

  • instability line — Meteorol. a nonfrontal line of convective activity in the atmosphere, usually several hundred miles long but of relatively brief duration. * * * …   Universalium

  • instability line — Meteorol. a nonfrontal line of convective activity in the atmosphere, usually several hundred miles long but of relatively brief duration …   Useful english dictionary

  • Horizontal convective rolls — producing cloud streets (lower left portion of the image) over the Bering Sea …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.