Setting Records in the Nation’s Capital

November 15 Snow in Poolesville, Maryland  (Courtesy: Ashley Adams)

Thursday’s snowfall in the DC Metro Area was its first measurable November snowfall since 1996.  A total of 1.4” fell at National Airport, breaking the November 15 record of 0.2” from 1906.  Meanwhile, 3” of snow was reported at Dulles Airport that shattered its previous November 15 record of a trace of snow that occurred most recently in 1995.  The American Meteorological Society (AMS) defines a trace of precipitation as “…an unmeasurable (less than 0.01 in.) quantity…”

A common misconception among Washingtonians is that November snowfall is a rarity.  The fact is that the Nation’s Capital averages 0.5” of snow in November.  Washington, D.C. has had snow in 15 of the past 30 Novembers from 1987 – 2017.  However, only a trace of snow occurred in 11 of those 15 winters.  That helps illustrate that while snow isn’t uncommon in DC during the month of November, measurable snowfall is rarer.  According to the National Weather Service, yesterday’s snow was DC’s largest November snow since 1989 when 3.5” occurred.  Longtime Washingtonians may recall that DC’s snowiest November occurred in 1987 (11.5”).

Yesterday’s precipitation was significant for another reason as well.  The total of 1.15” of rain (and liquid snow equivalent) that occurred in DC pushed the total to 58.53” since January 1.  That made 2018 DC’s fourth wettest year on record, with six more weeks to go.  Also, a total of 5.67” of rain has fallen at National Airport (DC’s official weather reporting site) since November 1.  That ranks among DC’s 10 wettest Novembers on record.

Select November 15 Snow Totals (Source: National Weather Service)

DC

National Zoo – 2”

Maryland

Clarksburg – 5.2”
Frederick – 5.0”
Rockville – 2.7”
BWI Airport – 1.7”


Virginia

Leesburg – 5.0”
Dulles International Airport – 3.0”
Wolf Trap – 2.7”
National Airport – 1.7”

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Washington, D.C.’s Ten Wettest Novembers (Source: NOAA)

1.  7.18”  (1877)
2.  6.70”  (1963)
3.  6.43”  (1932)
4.  6.33”  (1952)
5.  6.05”  (1972)
6.  6.03”  (1889)
7.  6.00”  (1948)
8.  5.77”  (1970)
9.  5.33”  (1988)
10.  5.29”  (1926)

Average: 3.17”

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Washington, D.C.’s Five Wettest Years (Source: NOAA)

1.  61.33” (1889)

2.  60.83” (2003)

3.  60.09” (1878)

4.  58.17” (1886)

5.  57.54” (1948)

Average: 39.74”