First, model agreement on the track of the storm is not ideal at this point. There are some differences between the global model solutions [the GFS and the GGEM being the furthest southeast, and the ECMWF being the furthest northwest of the global guidance], but nearly as severe as the differences between the global solutions and the mesoscale-model solutions, most notably with the NAM. While the GFS is indicating a weaker primary low tracking into C. Pennsylvania, the NAM is indicating that the low-pressure system will track from S. Indiana and into SW Ohio, with the low tracking just to the south of Toledo. As you can see, there is still some relative uncertainty as to the track of the storm. If the GFS's rather progressive solution verifies [which is possible, but unlikely], we will likely see a longer period of light-moderate snow, with some heavier snowfall rates in the deformation zone behind the storm. Snow-ratios would be rather high, and in combination with QPF totals of 0.3-0.5 inches [according to the GFS; not a forecast], we would see snow-totals in the range of 5-9". That is still rather impressive with how far east the GFS solution is. If the NAM's more-amped and western solution verifies, most of the area will see a long duration of heavy snow, with sleet and freezing rain mixing in for those who are near Lima and southeast. QPF totals, if this solution were to verify, would be in between 0.6-1", yielding snow totals around 8-12". At this point, it is hard to say which model is correct. The shortwave itself has not made it onshore yet to be sampled by the upper-air data. However, where the current wave is located is not in a data sparse region and just offshore of the West-Coast. Tonight will then be the night when we should see the final model trends coming into play.
At this point, I am favoring a compromise between the NAM and the global models. The NAM is likely too far northwest. Even though these types of events tend to lean "left-of-track", the NAM probably isn't handling the offshore energy all too well just yet. By tonight and early tomorrow morning, the NAM should have a better handle on the storm, and will most likely shift southeast. On the other-hand, the global models are likely too progressive. With the presence of a strong Hudson Bay vortex in a farther west position, it puts the storm in a prime position to take a shift west. Not only this, but it appears that the global models are too flat with the initial shortwave ejecting out of the SW. Even though a strong shortwave will flatten the SE ridge slightly today and tomorrow, rebuilding heights behind the system should cause the next storm-system to go much farther northwest, hence my preference towards a compromise. Given this, I expect that the storm will track from the lower Mississippi Valley [Arkansas, Louisiana, Mississippi, etc.] into Kentucky and then into Eastern Ohio. Until I have seen other-wise, I do not expect a track farther west than that. And given the above reasons, I do not believe the storm has as significant chance of taking the further south and east route. Either way, the storm will be weakened and shoved eastward by the development of a secondary low by late Tuesday night into Wednesday morning. Whether this has a significant impact on snow totals or not is too difficult to pinpoint at this time.
And as for the overall event, given the uncertainty above, I cannot give any details with any exactness or uncertainty, but at this point, I am expecting an all-snow event for most of the area. If the farther north track verifies, some portions of the area, especially near Lima and southeast could see periods of sleet and freezing rain, but that's about all of the mixing that we will have to worry about. Snow totals should range around 6-10", with the possibility of 8-12" if a stronger and slower system verifies. As for timing, there is still too much uncertainty to say anything for certain at this point.