# ECMWF AIFS

ECMWF's AI-based forecasting model that provides global weather forecasts at 0.25° resolution.

## Live Forecast Data

* Global coverage at 0.25° resolution (721x1440 grid)
* Four daily runs (00, 06, 12, 18 UTC)
* 20-day prediction horizon (480h, six-hourly)
* 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

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

| Parameter Code | API Name                                       | Description                                    | Units                |
| -------------- | ---------------------------------------------- | ---------------------------------------------- | -------------------- |
| 2t             | air\_temperature\_at\_height\_level\_2m        | Air temperature at 2m                          | K                    |
| 2d             | dew\_point\_temperature\_at\_height\_level\_2m | Dew point temperature at 2m                    | K                    |
| r              | relative\_humidity\_at\_height\_level\_2m      | Relative humidity at 2m                        | %                    |
| 10si           | wind\_speed\_at\_height\_level\_10m            | Horizontal wind speed at 10m                   | m s⁻¹                |
| 10wdir         | wind\_direction\_at\_height\_level\_10m        | Horizontal wind direction at 10m               | Degrees true         |
| 100si          | wind\_speed\_at\_height\_level\_100m           | Horizontal wind speed at 100m                  | m s⁻¹                |
| 100wdir        | wind\_direction\_at\_height\_level\_100m       | Horizontal wind direction at 100m              | Degrees true         |
| msl            | air\_pressure\_at\_mean\_sea\_level            | Mean Sea-level Pressure                        | Pa                   |
| z\_500         | geopotential\_at\_pressure\_level\_50000Pa     | Geopotential                                   | m² s⁻²               |
| hcc            | high\_type\_cloud\_area\_fraction              | Cloud fraction in high levels of troposphere   | range between \[0,1] |
| mcc            | medium\_type\_cloud\_area\_fraction            | Cloud fraction in medium levels of troposphere | range between \[0,1] |
| lcc            | low\_type\_cloud\_area\_fraction               | Cloud fraction in low levels of troposphere    | range between \[0,1] |
| tp             | precipitation\_amount\_sum\_6h                 | Total Precipitation                            | mm m⁻²               |
| ssrd           | surface\_downwelling\_shortwave\_flux\_sum\_6h | Surface solar downward irradiance              | J m⁻²                |

### Additional Variables on Request

| Parameter Code | API Name                                               | Description                                                                      | Units   |
| -------------- | ------------------------------------------------------ | -------------------------------------------------------------------------------- | ------- |
| tcwv           | atmosphere\_mass\_content\_of\_water\_vapor            | Total column vertically-integrated water vapour                                  | kg m⁻²  |
| t              | air\_temperature\_at\_pressure\_level (at 13 levels)   | Temperature at a specified pressure level                                        | K       |
| u              | eastward\_wind\_at\_pressure\_level (at 13 levels)     | U component of wind                                                              | m s⁻¹   |
| v              | northward\_wind\_at\_pressure\_level (at 13 levels)    | V component of wind                                                              | m s⁻¹   |
| q              | specific\_humidity\_at\_pressure\_level (at 13 levels) | The mass of water vapour per kilogram of moist air at a specified pressure level | kg kg⁻¹ |
| z              | geopotential\_at\_pressure\_level (at 13 levels)       | The gravitational potential energy of a unit mass                                | m² s⁻²  |

Note: The previous naming convention used in EPT-1.5 is deprecated. All new integrations should use the standardized naming shown above.

## Hindcast Data

**Spatial Extent:** Global, on a grid of 721x1440 (25 km resolution).

**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**        | **Temporal Extent**                                            | **Forecast Horizon and Resolution** |
| ---------------- | -------------------------------------------------------------- | ----------------------------------- |
| AIFS-Single v1.1 | <p>2025-01-06 06:00:00 - today</p><p>at 00, 06, 12, 18 UTC</p> | 480h, six-hourly                    |


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