Webberweather53
Meteorologist
Back in the early 90's we had a convective thundersnowstorm....it was early March with a lot of sun in the morning and very cold air aloft.....several distinct county sized "storms" formed around lunchtime, it was maybe 40-42 degrees as the storm moved in and you could see the "precip" falling as it moved in, basically a white wall....the edge was rn/sn/graupel mix but once the leading edge was past it was dumping big fat wet flakes the size of golf balls, temps crashed to near freezing.....it even mixed with graupel at the height of the precip.....it quickly covered everything including the roads and a few slushy inches piles up in 30-40 mins....as soon as it was over the sun came out and it was mostly melted in a hr or two....one of the crazier weather experiences I have had.
I'm personally guessing this is March 8-9 1996? I haven't mapped that particular event yet but the large-scale pattern, temperature, and precipitation data generally seem to fit the description you've outlined here