Currently reporting:
KJYO LEESBURG/GODFREY distance: 4.54 miles. WNW
@ 2019-09-15  20:15 UTC,
     KJYO 152015Z AUTO 34007KT CLR 28/13 A3014 RMK AO2
KIAD WASH DC/DULLES distance: 7.89 miles. SSE
@ 2019-09-15  19:52 UTC,
     KIAD 151952Z VRB05KT 10SM CLR 29/11 A3012 RMK AO2 SLP194 T02940106
KGAI GAITHERSBURG distance: 19.18 miles. ENE
@ 2019-09-15  19:56 UTC,
     KGAI 151956Z AUTO 00000KT 10SM CLR 28/12 A3014 RMK AO2 SLP214 T02830122
KHEF MANASSAS MUNI distance: 22.66 miles. S
@ 2019-09-15  19:56 UTC,
     KHEF 151956Z 24007KT 10SM CLR 31/12 A3011 RMK AO2 SLP199 T03060117
KFDK FREDERICK distance: 26.56 miles. NNE
@ 2019-09-15  19:47 UTC,
     KFDK 151947Z 04006KT 10SM SKC 31/12 A3012
KDCA WASHINGTON/NATL distance: 27.83 miles. ESE
@ 2019-09-15  19:52 UTC,
     KDCA 151952Z 27005KT 10SM FEW030 FEW050 FEW250 31/11 A3011 RMK AO2 SLP196 T03110111
KDAA FORT BELVOIR/DAV distance: 28.43 miles. SE
@ 2019-09-15  19:56 UTC,
     KDAA 151956Z AUTO 27004KT 10SM CLR 31/12 A3010 RMK AO2 SLP195 T03090123 $
KCGS COLLEGE PARK distance: 30.92 miles. E
@ 2019-09-15  20:02 UTC,
     KCGS 152002Z AUTO 00000KT 10SM CLR 29/07 A3010 RMK AO1 T02920067
KHWY WARRENTON distance: 34.12 miles. SSW
@ 2019-09-15  20:15 UTC,
     KHWY 152015Z AUTO 34006KT 10SM CLR 31/10 A3012 RMK AO2 T03060095
KOKV WINCHESTER RGNL distance: 36.07 miles. W
@ 2019-09-15  20:15 UTC,
     KOKV 152015Z AUTO 00000KT 10SM CLR 28/11 A3012 RMK AO2
KMRB MARTINSBURG distance: 36.2 miles. NW
@ 2019-09-15  19:53 UTC,
     KMRB 151953Z AUTO 00000KT 10SM CLR 29/10 A3012 RMK AO2 SLP195 T02940100
KADW ANDREWS AFB distance: 36.87 miles. ESE
@ 2019-09-15  19:56 UTC,
     KADW 151956Z AUTO 26003KT 10SM CLR 30/12 A3011 RMK AO2 SLP201 T03000115 $
KFME FORT MEADE distance: 38.76 miles. E
@ 2019-09-15  20:03 UTC,
     KFME 152003Z AUTO 26005KT 10SM 29/11 A3013 RMK AO1
KNYG QUANTICO MCAF distance: 39.15 miles. SSE
@ 2019-09-15  19:56 UTC,
     KNYG 151956Z AUTO 18007KT 10SM CLR 29/18 A3011 RMK AO2 SLP197 T02940178 $
KCJR CULPEPER distance: 40.76 miles. SSW
@ 2019-09-15  20:15 UTC,
     KCJR 152015Z AUTO 36006KT 10SM CLR 30/11 A3012 RMK AO2 T03010113
KFRR FRONT ROYAL distance: 41.89 miles. WSW
@ 2019-09-15  20:15 UTC,
     KFRR 152015Z AUTO 00000KT 10SM CLR 28/11 A3013 RMK AO1
KBWI BALTO/WASH INTL distance: 43.94 miles. ENE
@ 2019-09-15  19:54 UTC,
     KBWI 151954Z VRB05KT 10SM FEW065 FEW120 FEW250 32/09 A3010 RMK AO2 SLP190 CB DSNT E MOV NE T03170089
KRMN STAFFORD REGNL distance: 44.53 miles. S
@ 2019-09-15  20:15 UTC,
     KRMN 152015Z AUTO 00000KT 10SM CLR 30/15 A3015 RMK AO2 T03000150
KDMW CARROLL CNTY distance: 46.43 miles. NNE
@ 2019-09-15  20:00 UTC,
     KDMW 152000Z AUTO 00000KT 10SM CLR 29/13 A3014 RMK AO2
KHGR HAGERSTOWN distance: 47.2 miles. NNW
@ 2019-09-15  19:53 UTC,
     KHGR 151953Z 00000KT 10SM CLR 28/11 A3013 RMK AO2 SLP207 T02830111
KDMH BALTIMORE/DWNTWN distance: 49.49 miles. ENE
@ 2019-09-15  19:54 UTC,
     KDMH 151954Z AUTO 30/11 A3010 RMK AO1 SLP193 T03000111

Not current (maybe part-time, military or newly obsolete)
KW32 CLINTON distance: 36.05 miles. SE
KRSP NSF THURMONT distance: 41.9 miles. N
KJWX FORT RITCHIE distance: 46.64 miles. N
KRYT FOUNTAIN DALE distance: 47.73 miles. N