METEOROLOGIST JEFF HABY
1. What is CINH?
CINH (Convective Inhibition in units of Joules per kilogram) is anti-CAPE (negative CAPE) in the lower
troposphere. This is the region where a parcel of
air if raised from the lower
PBL would sink back down again. Another term for CINH is a
capping layer. The
capping layer must be broken before lower PBL based lifting is able to move into the +CAPE region of
a sounding and develop into deep convection.
2. How is CINH determined?
CINH is the area of the sounding between the surface and to the level at which +CAPE begins. In the CINH
region the parcel will be cooler than the surrounding environment-- thus this is a stable layer. The sounding
at the bottom of this page shows a CINH value 37 J/kg. This is a weak cap, especially considering daytime
heating has not even begun. Convection will likely start early this day.
3. Operational significance of CAPE:
|0 - 50 ||Weak Cap||51 - 199 ||Moderate Cap
||200+ ||Strong Cap
CINH will be reduced by: 1) daytime heating,
2) synoptic upward forcing,
3) low level convergence,
4) low level warm air advection
(especially if accompanied by higher
dewpoints). CINH is most likely
to be small in the late afternoon since daytime heating plays a crucial role in reducing CINH.
a. Index is only relevant to lower PBL based convection. Index is usually only relevant in a
environment or in the warm sector of a mid-latitude cyclone.
b. Index is only relevant when there is a cap to be broken. If no +CAPE exists above PBL, then the CINH value is
c. Keep in mind the factors that day that will either enhance or reduce the
capping inversion. See