The European Centre for Medium-Range Weather Forecasts (ECMWF) has upgraded its Integrated Forecasting System (IFS) to Cycle 47r2, leading to improved forecasts, according to the organization.
The upgrade, implemented on May 11, has introduced a single precision for high-resolution (HRES) and ensemble forecasts (ENS), and increased the vertical ensemble resolution. The changes come ahead of a more substantial upgrade to be introduced once ECMWF’s new supercomputer in Bologna, Italy, is up and running.
According to ECMWF, the change from double precision (64-bit accuracy) to single precision (32-bit accuracy) in many of the calculations carried out for forecasts is neutral in terms of performance, but it frees up about 40% of computing power for improvements. Furthermore, the increase in ENS vertical resolution from 91 levels to the current HRES vertical resolution of 137 levels leads to significant improvements.
The increase in vertical resolution has been applied to all ENS forecasts in the medium to the extended range. According to ECMWF, it leads to statistically significant improvements to many ENS scores of about 0.5 to 2% throughout most of the free troposphere. Stratospheric temperature scores are greatly improved, typically by 5 to 20%.
In a news story on its website, ECMWF said, “The change to single precision in the HRES and ENS systems has freed up computing resources. This has been used to increase the vertical resolution of ENS, which has enhanced many aspects of forecast skill across different time ranges.”
For the full story and for more information on the IFS Cycle 47r2, click here.