Agreed, it isn't easy for a storm that produces that much rain over Tennessee to slide off the coast to our south, especially when there is a high moving offshore.
That is a weird looking pattern on the December 9th storm. The only Analog I can think of is the PDII. Maybe something in February 1998 looks close at 500mb, but none of those were snow for us.
One more thing. This storm produced about a 5-6f of wetbulb + dynamic cooling. Temps dropped from about 36f-30f between between 4 and 8 am when the precip moved in. This helped cause the disaster on the roads.
Made it back from king of Prussia. It's worse in Frederick than anywhere along I95, I70, I695. Glad I waited for 32 and rain before I left.
They are just starting to get Frederick cleaned up now.