This article would be more suited for a meteorological technician or expert. It is also ideal for a weather enthusiast with a good knowledge about meteorology.
Summary
On 12 November 2024, there was an upgrade of the IFS (Integrated Forecasting System) of the ECMWF (European Centre for Medium-Range Weather Forecasts). This upgrade was the Cycle 49r1.
The major gains from this upgrade are in the near-surface wind predictions. Temperature predictions also improved. These gains are especially notable for the winter months in the northern hemisphere.
For the first time it has included the assimilation of the 2-metre temperature observation data, which, through a change in the Ensemble of Data Assimilation, helped to set and give estimates of the initial conditions and its uncertainty.
This upgrade also helped to determine the uncertainty of the ensemble forecast, through a new scheme.
Other improvements have been achieved in the use of observations. These observations are for the initial conditions of forecast. Additionally, there have been changes in the surface wind wave model.
Near-surface wind and temperature predictions
After assimilating the 2-metre temperature data in the 4D-Var system, an improvement was observed. This enhancement was seen in the physical representation of processes which, thus, positively affected the temperature forecast.
A new scheme for model uncertainty, called SPP ( Stochastically Perturbed Parametrization), replaced an old one, closing more the gap towards the sources of errors.
The use of new observations was also important. One example is the use of microwave imaging radiances over sea-ice surfaces for the 4D-Var.
Data coming from the AMSR2 (Advanced Microwave Scanning Radiometer 2) and GMI (Global Precipitation Measurement Microwave Imager), for sea ice and surroundings , improved the forecast near Antarctica (averaging 0,5% up to day 4) .
The ocean wind wave model has been improved, both scientifically and technically, in the horizontal grid which now measures 9 and 36 km in the medium-range and sub-seasonal forecasts, respectively.
That also helped the forecast of the wave height and, then, the atmospheric temperature forecast performance.
Final remarks
Wave parameters are passed to other Earth system components in sea-ice conditions. This points at the possible importance of wave–sea-ice interactions. Work has started on adding these interactions, with potential for future progress.
Future work should investigate whether introducing some processes, e.g.: the role of sea spray and active wave breaking in the calculation of ocean surface fluxes is beneficial. These occur under extreme wind situations. So, when modeling such extremes becomes possible, it can improve calculations.
One important aim of ECMWF is to run forecasts at kilometre scale !
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