> For the complete documentation index, see [llms.txt](https://docs.jua.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.jua.ai/models-and-products/third-party-models/ecmwf-aifs-ens.md).

# ECMWF AIFS Ensemble

The ECMWF AIFS Ensemble (AIFS ENS) is ECMWF's data-driven (AI) global ensemble, providing a control forecast plus 50 perturbed-forecast members. Jua serves it from ECMWF Open Data.

## Live Forecast Data

* Global coverage at 25 km resolution (720x1440 grid)
* Four daily runs (00, 06, 12, 18 UTC)
* 360h forecast (15 days) for every run
* 6-hourly time steps throughout (0–360h)
* Real-time data access via [Python SDK](/python-sdk/weather/forecast.md) or [REST API](/api-v2/getting-started.md)

## Technical Specifications

### Available Weather Parameters

ECMWF AIFS ENS uses standardized variable naming conventions. For full details on the naming structure, see [Weather Variable Naming](/python-sdk/weather/naming.md).

| Code    | API Name                                       | Description                       | Units        |
| ------- | ---------------------------------------------- | --------------------------------- | ------------ |
| 2t      | air\_temperature\_at\_height\_level\_2m        | Air temperature at 2m             | Kelvin       |
| 2d      | dew\_point\_temperature\_at\_height\_level\_2m | Dew-point temperature at 2m       | Kelvin       |
| skt     | surface\_temperature                           | Surface (skin) temperature        | Kelvin       |
| 10si    | wind\_speed\_at\_height\_level\_10m            | Horizontal wind speed at 10m      | m s⁻¹        |
| 100si   | wind\_speed\_at\_height\_level\_100m           | Horizontal wind speed at 100m     | m s⁻¹        |
| 10wdir  | wind\_direction\_at\_height\_level\_10m        | Horizontal wind direction at 10m  | Degrees true |
| 100wdir | wind\_direction\_at\_height\_level\_100m       | Horizontal wind direction at 100m | Degrees true |
| sp      | surface\_air\_pressure                         | Surface pressure                  | Pa           |
| msl     | air\_pressure\_at\_mean\_sea\_level            | Mean Sea-level Pressure           | Pa           |
| tp      | precipitation\_amount\_sum\_1h                 | Total Precipitation               | mm m⁻²       |
| ssrd    | surface\_downwelling\_shortwave\_flux\_sum\_1h | Surface solar downward irradiance | J m⁻²        |

## Hindcast Data

**Data Access:** Hindcasts are available via [API](/api-v2/getting-started.md) or [SDK](/python-sdk/getting-started.md). For bulk, grid-based access, please contact <support@jua.ai>.

| **Model**      | **Spatial Extent**                       | **Temporal Extent** |
| -------------- | ---------------------------------------- | ------------------- |
| ECMWF AIFS ENS | Global, 25 km resolution (720x1440 grid) | 2025-07-01 - today  |


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