ECMWF Integrated Forecast System Wave Ensemble Forecast (IFS Waef)

Description

The IFS Wave Ensemble Forecast (IFS Waef) is ECMWF's probabilistic ocean wave guidance. It couples the WAM wave model with the atmospheric IFS, producing 51 equally likely members (50 perturbed + 1 control) every six hours. By sampling model and initial condition uncertainty, IFS Waef delivers a spread of plausible sea state scenarios—crucial for offshore operations, coastal engineering, and voyage optimisation.

This open data subset provides global wave fields on a 0.4° grid (≈45 km) in GRIB2 format, extending out to 360 h (15 days) for the 00 UTC and 12 UTC cycles. All ensemble members are mirrored to AWS for fast, cost free access inside AWS regions and served via GribStream for sub setting and on the fly aggregation.

Detail

• Product page: https://www.ecmwf.int/en/forecasts/datasets/open-data
• Key Features:
  • 51 member ensemble (50 perturbations + 1 control) with ensemble mean and spread files.
  • 0.25° global coverage.
  • 00, 06, 12 & 18 UTC cycles: steps 0h to 144h every 3h, 150h to 360h every 6h.
  • Released ~1 h after the ECMWF real time dissemination schedule.
  • Parameters include significant wave height (Hs), mean/peak period, mean/peak direction, swell partitions, Stokes drift, 2D spectra, and derived probabilistic products.
• Resolution: 0.25° (~28 km) global grid.
• Temporal Coverage: Four runs per day (00/06/12/18 UTC); forecasts out to 15 days.
• Primary Use Cases: Offshore logistics & safety, port operations, renewable energy yield, ship routing, coastal flood risk, research.

Parameters