- Created by Kathy Maskell, last modified by Emma Pidduck on Feb 28, 2025
This page has been revised as of to detail the AIFS file naming convention following operational implementation of AIFS Single v1 on 25 February 2025. These changes will take effect from the 06 UTC run.
Naming convention - IFS data
The following dissemination filename convention is used for the transmission of ECMWF dissemination products:
ccSMMDDHHIImmddhhiiE where:
- cc is Dissemination stream name
- S is dissemination data stream indicator
- MMDDHHII is month, day, hour and minute on which the products are based
- mmddhhii is month, day, hour and minute on which the products are valid at
- ddhhii is set to “______” for Seasonal Forecasting System products
- ii is set to 01 for high resolution forecast time step zero, type=fc, step=0
- E is the Experiment Version Number’ (as EXPVER in MARS, normally 1)
Dissemination data stream indicator
S | Description | Stream & Type (where applicable) |
|---|---|---|
| A | High resolution forecast Weather Parameter products (15-day) | stream=oper, type=wp |
| B | Ensemble forecast Weather Parameter products (15-day) | stream=enfo, type=wp |
| C | Tropical Cyclone high resolution trajectory forecast products (HRES) (15-day) | stream=oper/scda, type=tf |
| D | High resolution forecast products - atmospheric data (HRES) (15-day) | stream=oper (also scda for 06/18 if requested) |
| E | Ensemble forecast products- atmospheric data (ENS) (15-day) | stream=enfo (00/06/12/18) |
| F | Subseasonal forecast products - atmospheric data (ENS-extended) (46-day) | stream=eefo (was enfo) |
| G | Ensemble forecast products - high-frequency wave data (ENS-WAM) (15-day) | stream=waef |
| H | Subseasonal re-forecast products - atmospheric data (ENS-extended) (46-day) | stream=eefh/eehs (was enfh/efhs) |
| I | Ensemble reforecast products - atmospheric data (ENS) (15-day) | stream=enfh/efhs (new) |
| J | Ensemble reforecast products - wave data (ENS) (15-day) | stream=enwh/wehs (new) |
| L | Seasonal forecasting system products - atmospheric data (SEAS) | stream=mmsm/mmsf/mmsa |
| M | High resolution post-processed forecast products for 'Thermofeel' parameters (15-day) | stream=oper, type=fc (selected parameters only) |
| N | Seasonal forecasting system products - wave data (SEAS-WAM) | stream=wasf |
| O | Ensemble forecast post-processed forecast products for 'Thermofeel' parameters (15-day) | stream=enfo, type=pf/cf (selected parameters only) |
| P | High resolution forecast - wave data (HRES-WAM) (15-day) | stream=wave (00/12) |
| Q | High resolution forecast - high-frequency wave data (HRES-WAM) (15-day) | stream=scwv (06/18) |
| S | High resolution forecast - high-frequency atmospheric data (HRES) (15-day) | stream=scda |
| T | Tropical Cyclone ensemble trajectory forecast products (ENS) | stream=enfo, type=tf |
| U | Ensemble forecast post-processed products - wave data (e.g. ensemble means, extreme forecast indices) | stream=waef, type=em/efi/sot/ep |
| V | Subseasonal forecast products - wave data (ENS-WAM-extended) (46-day) | stream=weef (was waef) |
| W | Ensemble forecast products - wave data (ENS-WAM) (15-day) | stream=waef |
| X | Ensemble forecast products - high-frequency atmospheric data (ENS) (15-day) | stream=enfo |
| Y | Ensemble forecast post-processed products - atmospheric data (e.g. ensemble means, extreme forecast indices) (15-day) | stream=enfo, type=em/efi/sot/ep |
| Z | Subseasonal reforecast products - wave data (46-day) | stream=weeh/wees (was enwh/wehs) |
File format
Most products are encoded in WMO FM-92 GRIB edition 1, unless otherwise specified in our Catalogue of Real-time products
- Product subset I-i-c (High Resolution Atmospheric model), III-i-c (Ensemble Atmospheric model): Model level parameters encoded in WMO FM-92 GRIB edition 2
- Product subsets I-ii, III-iv (Time Series of Weather Parameters) and Products subsets I-iii, III-viii (Tropical Cyclones), encoded in WMO FM-94 BUFR
Create a support ticket in our Support portal
Naming - AIFS via dissemination
Taking into account user feedback, ECMWF has chosen to implement a new naming convention for the AIFS data via dissemination.
This only applies to AIFS data via Dissemination. Later, ECMWF may implement this for the IFS data also. We would welcome your feedback on this new naming convention.
The composition of the file will be comprised of MARS standard information such as class, stream, type in addition to a new MARS keyword ("model"), which identifies the AI model that produced the forecast. These MARS keys are combined with unique user identifiers such as Destination name and Feed name:
- User Destination name (i.e. ABC)
- User Feed name (i.e. A1)
- Model (e.g. aifs-single)
- Class (e.g. ai)
- Stream (e.g. oper)
- Type (e.g. fc or an)
- Production date (YYYYMMDD)
- Range/step
- Valid date (YYYYMMDD)
Therefore, an example filename would be:
Destination_Feed_Model_Class_Stream_Type_ProdDate_ValidDate_Step.grb ABC_A1_aifs-single_ai_oper_fc_20250219T060000Z_20250219T060000Z_0h.grb