Winter '18 / '19 - Arctic Oscillation (AO) Analog Verification
The analog forecasting technique seeks associations to the AO state in the run-up to the coming winter with AO run-up states of past winters. Presented here is the verification of AO analogs for the '18 /'19 winter.
The NEWxSFC method ranks analog years by their the sum of square errors (SSE) statistic.
Lower SSE errors ==> stronger analog
Constraining the number of analog winters for analysis to five is arbitrary.
In the run-up to Winter '18 / '19 ... '55 / '56 was the leading analog followed by '64 / '65 ... '84 / '85 ... '99 / '00 ... and '91 / '92. Observed AO values for Winter '18 / '19 began neutral in DEC ... turned weakly negative in JAN ... then surged positive at meteorological winter/s end and into MAR.
A quantitative assessment of the other '84 / '85 teleconnections ... not so much.
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