Deep trough, CAA, and a little PVA.
ORH had -SNRA in the early evening around 40°, but CON did it just before midnight with 29°.
CON,1992-10-01 05:00,KCON 010500Z 00000KT 7SM -SHSN OVC040 M02/M03 A3006 RMK SB39 VLGT SLP181 T10171028
CON,1992-10-01 06:00,KCON 010600Z 19004KT 7SM SCT040 SCT070 M02/M03 A3005 RMK SE12/ SLP179 60000 8/570 T10221033 57005