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Auxiliary Material for
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Do Extreme Climate Events Require Extreme Forcings?
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Arun Kumar1, Mingyue Chen1, Martin P. Hoerling2, Jon Eischeid2
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NOAA Climate Prediction Center, College Park, MD
NOAA Earth System Research Laboratory, Boulder, CO
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Geophysical Research Letters
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Figure S1. (a) Observed sea surface anomalies for May-June-July (MJJ) 2012, (b) CFSv2 MJJ
2012 predicted sea surface temperature anomaly from April 21-30 initial conditions. Unit is Deg
K.
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Figure S2. 200 hPa height anomalies for the (a) four best, (b) four worst CFSv2 predictions for
MJJ 2012, and (c) difference between four best and four worst predictions. The four best and
four worst cases were selected based on the skill of precipitation. Unit is in meters.
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Figure S3. (a) Spatial anomaly correlation between precipitation forecasts for MJJ 2012 between
for individual forecasts and the ensemble mean forecast. Ensemble of forecasts corresponds to
40 forecasts initialized between 21-30 April, 2012. Correlations for all 40 initial conditions are
shown, and correlations are arranged in an ascending order for precipitation. The ensemble
mean precipitation is based on 39 member ensemble and the individual forecast member which is
correlated with the ensemble mean is not included in the computation of ensemble mean. Spatial
correlation is computed over the NA in Fig. 2. (b) Same as for the precipitation but for SST.
The spatial domain for correlation is between 60oS-60oN. SST correlations are not arranged in
ascending order but correspond to the same forecast member as for the precipitation in the upper
panel.
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