Looks like a decent inversion. Thurmont mesonet site never dipped below 33°, but the low lands all got into the 20s. I just bumped into the low 30s once the sun came up.
Don't look now, but the extended 00z EPS cancels out any major warm up through New Year's. While the pattern does not appear favorable for a HECS, it sure as heck beat Pacific Puke for Christmas.