It’s the evil “inverted bow echo”.  Actually a storm splitting just north of CYS 23:48Z

Update 00:30Z  looking at total lightning along this storm…the following image represents total ltg. at the time of the above image.  Lightning dropped off quickly shortly after…at the same time the storm weakened as it went through a split/reorganization.  By 00:15 ltg had picked back up as the storm reorganized.  Storm as strong as it has been at 00:30 (74% on ProbSevere, 1.10″ MRMS MESH) but lightning as not picked back up to its previous high levels before the previous split…