GOES-R CI Probabilities Running Hot...

In a region of high instability (dew points in the low-mid 70's, MLCAPE values >5000 J/kg) the CI probabilities are frequently appearing in the 50-80% range, yet no CI is occurring. A region in far northeastern Oklahoma is highlighted between 2130 and 2215 UTC. Areas further to the northeast in Missouri are, in contrast, showing higher CI probabilities followed by convective storm development.

What is happening?

In these regions, in northeastern Oklahoma, it is speculated that an inversion near ~690 mb is inhibiting CI. Yet, within the CI algorithm, only lower level inversion information is being considered as a variable within the logistic regression equation. This is the suggested reason for the discrepancy between the GOES-R CI signatures/higher probabilities and the lack of storms in Oklahoma. The SPC Mesoscale Analysis (of MLCAPE) is shown below.

The figure below shows the 1200 UTC Springfield, MO sounding shows an inversion near 690 mb. Although this sounding is ~8 hours old, it would seem to suggest the inhibiting factor for the occurrence of deep convection is this inversion. Therefore, from the GOES satellite perspective, the cumulus are growing vigorously, and hence producing high CI probabilities, until this ~690 mb inversion is encountered.

John Mecikalski