Zonal Mean Zonal Wind

This page shows retrospective forecasts for the zonal mean zonal wind at 10hPa and 60N/S a typical metric used to diagnose dynamical activity in the stratosphere. Plots are constructed each Thursday and are delayed by three weeks from real-time. The analysed state from the NASA GEOS-5 model is shown as a comparison to show performance of the models. In all cases a simple bias correction based on the hindcast data is shown.

Ensemble mean forecast for all models

This figure shows the ensemble mean forecast for each model plotted against the ERA-Interim climatology. Each model estimate is bias corrected based on the time-evolving hindcast set available for each model. The black line shows the corresponding observed evolution derived from the independent GEOS-FP dataset.

Start Northern Hemisphere Southern Hemisphere Load Plot

Terciles

This figure shows the corresponding evolution of the probability of being in the weak, neutral or strong jet tercile for each model. The terciles for each model are selected based on the hindcast set of each model/p>

Weak Neutral Strong

Individual Models

This figure shows the corresponding evolution of an individual model ensemble for the forecast summarized in the first figure on this page. Quantities are averaged over each week of the forecast. The left distribution of each plot shows the PDF of the hindcast dataset for this model and the right distribution shows the PDF of the forecast. The lines in the centre of each distribution show the median and inter-quartile range for each distribution

Bureau of Meteorology China Meteorological Administration Institute of Atmospheric Science Meteo-France Environment and Climate Change Canada European Centre for Medium-Range Weather Forecasts Hydrometeorological Centre of Russia Japan Meteorological Agency Korea Meteorological Administration National Centres for Environmental Prediction Met Office