Baltimore Snow Climatology

I did a little digging, and came up with some surprising numbers inre to snow and the Mid-Atlantic.  Actually, the Subject Line shouldn’t be “Feast or Famine“, but rather “Lots of Famine, with a rare Feast“.  here are the details.

I was looking at the NAO data (North Atlantic Oscillation) and snowfall for BWI, and it showed what we already know: a negative phase of the NAO (a blocking high) is almost always required for snowy winters.  Not exclusively, but it’s a pretty strong driver.  What was more interesting is the shift in snow climatology for these parts, which is likely a function of the warmer climate regime we find ourselves in.  I went and grabbed the snowfall data for Baltimore (BWI), which goes back to 1950.  Now, I know there are people out there who will claim there’s some sort of conspiracy in the data, and I’ll admit snowfall is notoriously difficult to measure.  However, this only applies IF it’s snowing; I mean, if there’s no snow to measure, you can’t possibly screw that up.  The data is straight from the NWS… and valid for BWI.  Areas north and west of I-95 in the Piedmont typically get more snow, while areas south and east get less.  BWI is a happy medium ground for this region.

So, here it is… the moment that you’ve been waiting for. (if you’re still reading (and I can’t blame you if you threw in the towel))

Since 1950 (63 years), 10 of the 15 least snowy winters have occurred since 1990.  And 1988-89 makes the list but not the “since 1990” cutoff.  Here they are, rated in order…

BWI Snow Departure Winter Year Dud Rank
1.2 -16.8 1972-73 1
1.8 -16.2 2011-12 2
2.3 -15.7 2001-02 3
3.2 -14.8 1997-98 4
4.0 -14 1958-59 5
4.1 -13.9 1991-92 6
4.6 -13.4 1980-81 7
6.2 -11.8 1950-51 8
8.0 -10 2012-13 9
8.2 -9.8 1994-95 10
8.3 -9.7 1988-89 11
8.5 -9.5 2007-08 12
8.7 -9.3 2000-01 13
9.1 -8.9 2008-09 14
9.4 -8.6 1990-91 15

The departure from average is based on a normal of 18″.  My childhood being in the 70’s and 80’s (TMI, really), you can see how I grew thinking that snow was just a given.  Ha!!

On the flip side, 4 of the 15 most snowy, most awesomest winter have occurred since 1990.  (and don’t dare disagree with “awesomest”or you’ll be immediately removed from this list!).  But here’s the kicker.  The top 3 have all been since 1995.  here’s that list:

BWI Snow Departure Year Booyah Rank
77.0 59 2009-10 1
62.5 44.5 1995-96 2
58.1 40.1 2002-03 3
51.8 33.8 1963-64 4
46.5 28.5 1960-61 5
43.4 25.4 1966-67 6
43.0 25 1957-58 7
42.5 24.5 1978-79 8
35.6 17.6 1982-83 9
35.2 17.2 1961-62 10
35.2 17.2 1986-87 11
34.3 16.3 1977-78 12
34.1 16.1 1959-60 13
32.8 14.8 1965-66 14
26.1 8.1 1999-00 15

Winter #15, 1999-2000, most of this snow fell in one storm… the very January 2000 storm that was the birth of this list.

Anyhow, it appears that we have settled into a regime where the odds of getting hosed during winter have gone up, but so have the odds of the occasional blockbuster.  I can only hope we’re due.


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