Ensemble mean weekly anomalies

Forecast User Guide: Graphical Output

2-metre temperature

z500 (North Pole projection)

Regime products

Forecast User Guide: Extended Range Regime Charts

For discussion around the utility and verification, see:  https://www.ecmwf.int/en/newsletter/158/meteorology/new-product-flag-risk-cold-spells-europe-weeks-ahead

Extended Range Two-dimensional Regime diagram

Extended Range Weather Regime Frequency histogram

z500 Howmoller diagram

Forecast User Guide: Graphical Output

Drivers of predictability

Madden-Julian oscillation (MJO) index

Forecast User Guide: Madden-Julian Oscillation Output

Wheeler-Hendon MJO diagram

Teleconnection patterns from MJO in ERA-Interim (lag 10 days)

After phase 3 (left) and phase 6 (right)

Sudden Stratospheric Warmings (SSW)

Composites of weak and strong Polar Vortex (from Baldwin and Dunkerton, 2001):