VariabilityENSO: Mdl < ObsNEUT: Mdl > Obs

Obs

Mdl

ENSO NEUT

ElNino

LaNina

Neut

Potential Predictability

Raw forecast skill

Conventional bias corrected

Regime dependent bias corrected

Climate Variability and

Potential Predictabilityin CFS

Wilbur Y. Chen

Climate Prediction Center

NCEP/NWS/NOAA

Clim TotalVariance

Diff

MDL

OBS

More brown than blue

DML

OBS

DIFF

ENSODJFs

NEUTDJFs

MorePositive

More Negative

havehave

MDL

OBS

Ratio

ENSODJFs

NEUTDJFs

More

>> 1.

Less > 1.

A

B

A

B

MDL VAR of

ENS Means

Versus

ENS Spreads

ENS Means

ENSSpreads

Neutral

ENSO

Diff

Mdl Behavior:

clim noise is smallerwhen there is ENSO forcing

larger

smaller

Mdl VAR Ratio = Neutral / ENSO

More < 1.

More > 1.

Neut

ENSO

Ens mean Ens spread

Ratio

WarmDJFs

Cold DJFs

DIFF

ClimSignal

Clim Noise

MorePosit

MoreNegat

smaller

larger

larger

smaller

Potential Predictability

VAR of Clim Signal------------------------------------Total VAR (Signal+Noise)

El Nino DJFs

La Nina DJFsENSO

Total

Neut

El Nino DJFs

La Nina DJFs

for ENSO DJFs

for Neutral DJFs

Potential Predictability

Potential Pred: Warm vs Cold