MKX has an interesting discussion- seems as if they are being very tentative on things for Friday into Saturday, this seems a good explanation of why: “Models have started to trend toward a stronger deepening low that lifts NE Friday into Saturday. Previous guidance was flatter with the progression and kept some of the precip bottled up further south. This change would favor more precip wrapping into southeastern Wisconsin as the low pushes east. Now with that said, there are still some questions as to whether models have a good handle on the system. The initial low digs into MO/AR Thursday night into Friday and transitions into a closed low over the TN/OH Valleys. Then a second piece of energy digs south and this is what could cause the system to deepen as the two features phase over the OH Valley. The past few systems that have impacted the area have had a similar trend where 2-4 days (where we are currently) out models had more significant phasing and stronger lows which bumped up QPF totals. Then as you got closer in the 1-2 day period they backed off and QPF amounts trended back down. This has largely been the result of models inability to handle the phasing of closed lows. Will be keeping a close on eye on how guidance handles these features over the next few model cycles. Subtle adjustments to QPF were made with this forecast and these changes keep us below the 50th percentile for both QPF and Snow amounts. This is likely a good place to be based on the lingering uncertainty. Both GFS and ECMWF ensemble guidance are narrowing in on some of those higher QPF and snow amounts. So, if models hold onto this trend will likely continue to nudge amounts upwards. Another complicating factor is that with the low deepening warmer air gets wrapped in and temps Friday through Saturday could be such that we end up with more of a mix of rain/snow than all snow. The profile aloft is cold enough for all snow but there could be a deep enough layer near the surface to melt some of the snow. Do think models could have a slight warm bias to temps and have nudged values down slightly but this would still support a rain/snow mix.”