Here’s the max base reflectivity forecast for 22:15 Z..again , notice the east/west line of convection along the IA/MO border.

Here’s the 23Z forecast.  Notice how the western edge of that east/west line seems to interact with the “real” convection line to the west…taking on less of a linear character and looking more like the individual cells we have been seeing so far.  The eastern edge of that east/west line remains linear and lifts to the northeast.

Here’s the 23Z CAPE forecast,  Notice we continue to see a persistent east/west oriented waveform along our southern domain boundary.  Non-damped boundary waves are being turned into peaks of instability, leading to convective response in the model.

Obviously, where a forecaster sees a radar feature in line with spurious model waves, they can discount it.  Of concern is when these features interact with/react to “actual” convective features the model is tracking.  This could lead to other spurious development or result in contaminating the character of any convection that wanders into the waveform.

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