Typically forecasters will utilize cloud top cooling and glaciation for an initial look into convective initiation. OCTANE cloud-top cooling clearly depicts the rapid intensification of an updraft with the quick change of colors (green to red). However, the OCTANE divergence component of this product helps to signify mature convection and a strong persistent updraft. Notice how there is no signal for cloud-top divergence (CTD) in the animated loop below (Figure 1). No signature for CTD and warming cloud-top temperatures became an apparent signature for failed convection.

Figure 1: OCTANE cloud-top cooling and divergence. Notice a rapidly developing updraft initiating south of the cluster of storms before it quickly warms as the storm fails to maintain strength.

Lightning cast clearly signifies a low probability for convection developing south of the main cluster. Additionally, day cloud phase distinction reveals an orphan anvil present in the storm that showed a quick signal for cloud-top cooling in the OCTANE product. Thus, failed convection led to no signal for a storm at the base reflectivity scan on radar.

Figure 2: Lightning cast V1 (left) and V2 (right), along with GLM Flash Extent Density and Day Cloud Phase Distinction RGB.

Figure 3: Local radar KILX base reflectivity at 0.5 degree tilt.

– Aurora Borealis