I noticed that in Andover too that day. I think part of it, is due to wind just advecting air that isn't latently rotting at 32.000001F. IOW, get a little off the ground and you'll probably get a nice breeze of 31.5F air, vs near the ground where the air is stale and rotting at 32.000001F.
KORH had this phenomenon on roids where the T/TD was maybe 2-3F apart. They weren't in the clouds even in this setup. So you had a 20kt NE wind of like 30/27 or something like that. Just continuously advecting in prime icing air.