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Although simply constructed, the indices do have a part to play in assessment of any potential convection, particularly when used in conjunction with other meteorological information (e.g. low-altitude convergence, bulk shear, atmospheric cooling at higher altitudes etc.)  Users may have become accustomed to using an appropriate preferred instability index for their region of interest, but for a more detailed and comprehensive assessment users are encouraged to use these alongside forecast values of CAPE (Convective Available Potential Energy) and CAPE-shear, and CIN (Convective Inhibition). All such parameters are available in ecCharts.

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The values of the parameters and indices at Paris (location shown by the pin) are shown in the probe box and the vertical profile product for the same location is shown on the left. The vertical profile shows very dry air at 700hPa with a low dewpoint (about -35°C) which has a direct influence on evaluation of the K-index (CONTROL-10/HRES suggests -4.3°C!).  Some ensemble members, however, show air at 700hPa being moister (dewpoint as high as -5°C) and would therefore produce a higher K-index. Therefore the CONTROL-10/HRES value may well be extreme. A glance at the CAPE diagram suggests about a third of the ensemble members could permit instability release, albeit weak. In contrast to the CONTROL-10/HRES K-index, the CONTROL-10/HRES Total totals index (43.3°C, just within the yellow area) suggests that the thunderstorm risk is borderline. Instability indices on ecCharts are derived from CONTROL-10/HRES forecast values and the user must always bear in mind that ensemble values may be quite different. If possible they should compare with those via local workstation tools.

_{Updated/Amended 30/12/19 - Link to issue with CIN}

_{Updated/Amended 02/07/20 - Removed link to issue with CIN. Not applicable with 47R1.}