Winter '18 / '19 - ENSO ... Arctic Oscillation ... & Season-total Snowfall @NEWxSFC Stations (Wonkish)

Roosting snow crows rooting for bonus snows thanks to expected weak-to-moderate El Niño conditions.

Typical analysis ignores influence of other controlling factors ... such as the Arctic Oscillation (AO).

BLUF:  ENSO state does not provide robust guidance for season-total snowfall (STP) outcomes @NEWxSFC stations unless AO is considered.

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Analysis period:  '66 / '67 to '17 / '18 (D-J-F-M)
n = 52

For all winter ENSO states ... if AVG D-J-F-M AO < 0 … then STP @NEWxSFC stations > AVG
Weak correlation:  R = -0.311

Correlation (R) >= +/- 0.6 considered generally to have useful predictive power

ONI = Oceanic Niño Index


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La Nina
Strong (ONI <= -1.5)
AO < 0 ==> STP > AVG
AO > 0 ==> STP < AVG
Moderate negative correlation:  R = -0.549

Moderate (-1.5 < ONI <= -1)
AO < 0 ==> STP > AVG
AO > 0 ==> STP < AVG
Strong negative correlation:  R = -0.881

Weak (-1 < ONI <= -0.5)
AO < 0 ==> STP > AVG
AO > 0 ==> STP < AVG
Moderate negative correlation:  R = -0.623

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La Nada
Cool (-0.5 < ONI < 0)
No correlation R = 0.145

Warm ( 0 < ONI < 0.5)
No correlation R = 0.098

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El Niño
Strong (ONI >= 1.5)
AO < 0 ==> STP > AVG
AO > 0 ==> STP < AVG
Strong negative correlation:  R = -0.842

Moderate (1 <= ONI < 1.5)
AO < 0 ==> STP > AVG
AO > 0 ==> STP < AVG
Moderate negative correlation:  R = -0.507

Weak (0.5 <= ONI < 1)
No correlation R = -0.019

Bottom line:
Correlation between ENSO & season-total snowfall @NEWxSFC stations influenced strongly by D-J-F-M AO state.

The Challenge: forecasting winter/s average AO state.
MET Office's method here
NEWxSFC method here