Thanks Don. I am starting to lean towards the lower end given the guidance.
You may have the date, however, it was either january 1993 or 1994 (the cold and icy winter) which had a similar setup to this. Believe the city was 5 degrees in the morning and within 5 or 6 hours flipped to sleet (i do not recall the exact amount that fell). Boston was all snow and received over a foot.
This setup and cold air in place seems like a carbon copy. Perhaps can be used as a guide on thos event.