850mb clearly colder on 18z vs 12z. Not a ton, but noticeable shift toward colder/SE solution. 700mb pretty much a wash across the region compared to 12z.
With that initial WAA band pre-dawn Thursday, we get an extra 2-4", then another ~1" of snow, and then the sleet bomb (maybe 1-2" of sleet?). I'd take that verbatim.
Missing that WAA snow band on the NAMs is a key difference. GFS has that band right through DC. 0z Euro has some weak precipitation in PA where the NAM has it, but fills in the precip over us quickly as snow.
That difference is likely driven by that 700mb jet streak @MN Transplant showed. NAM is wwwaayyyy further north with that then any other guidance.