February 18-19, 1979 - "PDI" - DCA 18.7" (#3), BWI 20.0" (#8), IAD 16.3" (#6)
February 11, 1983 - DCA 16.6" (#6), BWI 22.8" (#5), IAD, 22.8" (#3)
March 13-14, 1993 - "Superstorm of '93" - not top-10 at DCA/BWI, 14.1" at IAD (#8)
February 10-11, 1994 ice storm
January 7-9, 1996 - "Blizzard of '96" - DCA 17.3" (#5), BWI 26.6" (#2), IAD 24.6" (#2)
January 25, 2000 - not top-10 at airports
February 15-17, 2003 - "PDII" - DCA 16.4" (#7T), BWI 26.8" (#1), IAD 21.7" (#4)
December 18-19, 2009 - "Snowpocalypse" - DCA 16.4" (#7T), BWI 18.0" (#10), IAD 18.0" (#5)
February 5-6, 2010 - "Snowmageddon, part 1" - DCA 17.8" (#4), BWI 25.0" (#4), IAD 32.4" (#1)
February 9-10, 2010 - "Snowmageddon, part 2" - not top-10 at DCA/IAD, BWI 19.5" (#9)
3-day snowfall totals from http://www.erh.noaa.gov/lwx/winter/storm-pr.htm