Climate forecast: Sub-seasonal
A global dataset at 0.25° or 0.10° resolution providing calibrated sub-seasonal forecasts with a 30-day outlook. The dataset is based on the ECMWF extended range forecast and post-processed to ensure consistency with observed climate statistics.
Specifications
| Specification | Description |
| Experiment | Sub-seasonal forecast |
Forecast system | Extended range forecast provided by the European Center for Medium Range Weather Forecast (ECMWF), calibrated against observations. It is composed of 100 forecast members. |
| Reference dataset | ERA5/ERA5-Land reanalyses |
| Spatial Resolution | 0.25°x0.25° Global or 0.10°x0.10° global over continents |
| Temporal resolution | Daily values over a 30-day forecast horizon |
| Variables | Four essential variables (other available on demand): – Mean 2m temperature – Maximum 2m temperature – Minimum 2m temperature – Total precipitation |
| Delivery | Once a month on the 15th. |
| Format | Netcdf, other format possible depending on data volume |
Supplementary information
The sub-seasonal forecast dataset is statistically calibrated using a quantile-mapping approach based on the CDF-t (Cumulative Distribution Function transform) method, applied independently for each lead month and grid point.
Key methodological characteristics:
- Probabilistic calibration: all ensemble members are treated as equally likely and jointly used to estimate forecast probability distributions.
- Lead-time-dependent correction: calibration is performed separately for each monthly lead time to account for forecast drift.
- Non-stationarity handling: the CDF-t method allows model and observational distributions to evolve over time, avoiding the stationarity assumption of standard bias-correction approaches.
- ERA5-consistent climatology: forecast probabilities are computed relative to ERA5-based climatologies derived from the hindcast period.
The reference for the original seasonal forecast datasets is ecmwf.int/en/forecasts/datasets/set-vi
Availability
The data can be delivered according to your specifications, contact us for a quote.