*Season goes from December to February*

*ENSO Strenth based off Oceanic-Nino Index*

Colors: Red= Warm or Postiive Phase, Blue= Cold or Negative Phase, Green= Neutral Phase

Index Values

Philadelphia, PA
Season Snowfall total Climate Pattern Season Average
NAO PNA AO PDO EPO ENSO
SOI Nino 3.4 Strength
1972/1973 0.0" 0.36 -0.21 1.085 -0.467 0.20 -9.5 1.69 Strong El Nino
1997/1998 0.7" -0.227 0.93 -0.778 1.02 -0.81 -17.3 2.18 Strong El Nino
1991/1992 2.2" 0.568 0.703 1.095 0.280 -0.38 -18.9 1.67 Strong El Nino
1950/1951 2.8" -0.315 -0.640 -0.804 -1.315 -0.31 -11.0 -0.91 Weak La Nina
1958/1959 3.6" -0.260 -0.055 -0.385 0.043 0.25 -5.2 0.40 Neutral
2011/2012 3.7" 1.37 0.57 0.655 -1.34 -0.94 11.6 -0.93 Weak La Nina
2001/2002 4.0" 0.350 -0.160 0.454 -0.433 -0.80 -1.0 0.01 Neutral
1996/1997 5.8" -0.067 -0.013 -0.096 0.16 0.02 8.2 -0.51 Weak La Nina
2007/2008 6.3" 0.510 0.00 0.859 -0.765 -0.86 15.5 -1.32 Moderate La Nina
1980/1981 6.4" 0.69 0.843 -0.168 0.65 0.71 -0.5 -0.43 Neutral



Washington, DC
Season Snowfall total Climate Pattern Season Average
NAO PNA AO PDO EPO ENSO
SOI Nino 3.4 Strength
1972/1973 0.1" 0.36 -0.21 1.085 -0.467 0.20 -9.5 1.69 Strong El Nino
1997/1998 0.1" -0.227 0.93 -0.778 1.02 -0.81 -17.3 2.18 Strong El Nino
1975/1976 1.4" 0.227 -0.37 0.993 -1.53 -0.84 14.7 -1.71 Strong La Nina
2011/2012 2.0" 1.37 0.57 0.655 -1.34 -0.94 11.6 -0.93 Weak La Nina
2008/2009 2.0" -0.077 -0.58 0.259 -1.27 0.36 12.5 -0.85 Weak La Nina
1968/1969 2.4" -1.26 -1.50 -2.288 -1.16 -0.06 -6.1 0.91 Moderate El Nino
1998/1999 2.9" 0.643 -0.02 0.648 -0.47 -1.28 12.5 -1.59 Moderate La Nina
2012/2013 3.1" 0.023 -0.003 -0.168 0.65 0.36 -0.5 -0.43 Neutral
2001/2002 3.2" 0.350 -0.160 0.454 -0.433 -0.80 -1.0 0.01 Neutral
1952/1953 3.5" -0.196 0.86 -1.037 -0.20 -1.40 -5.5 0.13 Neutral