Fort Belvoir low of 15. Surprised how low that station gets being close to river and often colder than IAD. Open field/lack of surrounding concrete perhaps?
BWI: 5.3
DCA: 1.3
IAD: 7.2
RIC: 6.4
SBY: 4.6
Methodology: Fringed by several Miller B's and one southern slider + one fantastic storm track but BL temp issues = minimal accumulation