Currently reporting:
KJYO LEESBURG/GODFREY distance: 4.54 miles. WNW
@ 2019-11-20  06:35 UTC,
     KJYO 200635Z AUTO 35005KT 10SM OVC060 08/02 A2991 RMK AO2
KIAD WASH DC/DULLES distance: 7.89 miles. SSE
@ 2019-11-20  05:52 UTC,
     KIAD 200552Z 33004KT 10SM SCT055 OVC075 08/02 A2989 RMK AO2 SLP120 T00830017 10083 20072 53002
KGAI GAITHERSBURG distance: 19.18 miles. ENE
@ 2019-11-20  05:56 UTC,
     KGAI 200556Z AUTO 32003KT 10SM FEW055 OVC070 08/02 A2988 RMK AO2 SLP133 T00780022 10078 20061 53002
KHEF MANASSAS MUNI distance: 22.66 miles. S
@ 2019-11-20  05:56 UTC,
     KHEF 200556Z AUTO 00000KT 10SM OVC065 06/06 A2990 RMK AO2 SLP130 T00610056 10078 20061 53003
KFDK FREDERICK distance: 26.56 miles. NNE
@ 2019-11-20  06:35 UTC,
     KFDK 200635Z AUTO 36003KT 10SM OVC060 08/03 A2990 RMK AO2
KDCA WASHINGTON/NATL distance: 27.83 miles. ESE
@ 2019-11-20  05:52 UTC,
     KDCA 200552Z 34007KT 10SM OVC055 10/04 A2989 RMK AO2 SLP120 T01000039 10111 20083 53001
KDAA FORT BELVOIR/DAV distance: 28.43 miles. SE
@ 2019-11-20  05:56 UTC,
     KDAA 200556Z AUTO 00000KT 10SM OVC055 07/06 A2988 RMK AO2 SLP121 T00690057 10087 20068 53001 $
KCGS COLLEGE PARK distance: 30.92 miles. E
@ 2019-11-20  06:35 UTC,
     KCGS 200635Z AUTO 00000KT 10SM OVC050 07/04 A2988 RMK AO1 T00700037
KHWY WARRENTON distance: 34.12 miles. SSW
@ 2019-11-20  06:35 UTC,
     KHWY 200635Z AUTO 00000KT 4SM BR BKN050 OVC070 05/03 A2990 RMK AO2 T00450031
KOKV WINCHESTER RGNL distance: 36.07 miles. W
@ 2019-11-20  06:35 UTC,
     KOKV 200635Z AUTO 29004KT 10SM BKN035 OVC055 06/01 A2990 RMK AO2
KMRB MARTINSBURG distance: 36.2 miles. NW
@ 2019-11-20  05:53 UTC,
     KMRB 200553Z AUTO 31005KT 10SM FEW042 OVC060 08/01 A2989 RMK AO2 SLP124 T00780011 10094 20072 53005
KADW ANDREWS AFB distance: 36.87 miles. ESE
@ 2019-11-20  05:56 UTC,
     KADW 200556Z AUTO 00000KT 10SM BKN050 OVC075 08/06 A2987 RMK AO2 SLP122 T00760059 10092 20067 53001 $
KFME FORT MEADE distance: 38.76 miles. E
@ 2019-11-20  06:33 UTC,
     KFME 200633Z AUTO 00000KT 10SM OVC050 06/05 A2991 RMK AO1
KNYG QUANTICO MCAF distance: 39.15 miles. SSE
@ 2019-11-20  05:56 UTC,
     KNYG 200556Z AUTO 28004KT 8SM OVC060 08/06 A2990 RMK AO2 SLP125 T00780061 10094 20078 53001
KCJR CULPEPER distance: 40.76 miles. SSW
@ 2019-11-20  06:35 UTC,
     KCJR 200635Z AUTO 32003KT 10SM SCT050 BKN065 08/03 A2991 RMK AO2 T00750031
KFRR FRONT ROYAL distance: 41.89 miles. WSW
@ 2019-11-20  06:35 UTC,
     KFRR 200635Z AUTO 00000KT 10SM OVC041 05/03 A2990 RMK AO1
KBWI BALTO/WASH INTL distance: 43.94 miles. ENE
@ 2019-11-20  05:54 UTC,
     KBWI 200554Z 04006KT 8SM BKN048 OVC065 09/05 A2987 RMK AO2 SLP115 T00890050 10100 20078 53002
KRMN STAFFORD REGNL distance: 44.53 miles. S
@ 2019-11-20  06:35 UTC,
     KRMN 200635Z AUTO 00000KT 10SM BKN060 OVC075 07/07 A2994 RMK AO2 T00700070
KDMW CARROLL CNTY distance: 46.43 miles. NNE
@ 2019-11-20  05:25 UTC,
     KDMW 200525Z AUTO 03004KT 10SM BKN043 OVC050 08/03 A2987 RMK AO2
KHGR HAGERSTOWN distance: 47.2 miles. NNW
@ 2019-11-20  05:53 UTC,
     KHGR 200553Z AUTO 35004KT 8SM OVC055 08/01 A2989 RMK AO2 SLP134 T00830011 10094 20078 53005
KDMH BALTIMORE/DWNTWN distance: 49.49 miles. ENE
@ 2019-11-20  05:54 UTC,
     KDMH 200554Z AUTO 09/03 A2988 RMK AO1 SLP119 T00890028 10100 20089 53003

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