This is one of the more complex setups we've seen in the 2-4 day timeframe. Northern end of the wave is splitting off and the southern end is phasing, not to mention a few other disturbances coming in behind it. I could see wild swings in models up until the final 24hrs kind of like 12/26/10.
The surface low and the 500mb low are 800 miles apart on some models. The precip moves in lockstep with the baroclinic zone at this point. Even better if the baroclinic zone is further north In AL/MS so the low gets cranking earlier.
Euro is an outlier with both the northern and southern streams. Even if it turns out correct I don't think anyone should be taking it's solution literally yet. We're going to need perfect timing to get a HECS in this chaotic pattern.
Trend on CMC since showing the HECS, A lot less phasing now. However with the 500mb low tracking over us, there is still a good chance for an over-performing high ratio event kind of like 1/30/10.
CMC looks very similar to the January 1978 KU storm.
https://meteocentre.com/reanalyses/get_reanalyses.php?lang=en&mod=ncep&area=na&yyyy=1978&mm=01&dd=20&run=06