Dear User,
Welcome to the May edition (Nr. 9) of the Data Support News!
As ever, we're pleased to share recent developments to help you stay ahead of key changes. A copy is also shared in the ECMWF Forum and in our Data & Charts blog for future reference.
IFS Cycle 50r1 and AIFS v2 successfully implemented on 12th May 2026
As you probably have seen, IFS Cycle 50r1 and AIFS v2 were successfully implemented on 12th May 2026. We thank all users for their patience during the implementation, as well as all those who tested prior to the implementation date.
We'd like to use this opportunity to remind all users of the following points:
- It is your responsibility to review our communications for any potential impacts to your data flows.
- Test data may not be used in your operations or services, or published on social media. This will also be the case for future cycle implementations.
If you have any specific feedback on how we might improve in future, please don't hesitate to contact us via the ECMWF Support Portal.
Communicating details of contact information changes
During the implementation of the models' upgrade, we noticed a number of users had outdated or incorrect contact information that led to issues when implementing the changes. We would like to remind all that it is the responsibility of the user to inform us of any changes to contact details through the following page: Inform us of changes in your contact information.
End of LEGACY filenaming
With the implementation of IFS Cycle 50r2 (currently scheduled for Q1 2027), use of the LEGACY filenaming convention for IFS real-time products delivery via the ECMWF Production Data Store (ECPDS) will be discontinued. We advise that you review how this change will affect your activities and plan accordingly.
Further information is available on the File naming convention and format for real-time data page.
Note that National Meteorological Services of ECMWF Member and Co-operating States will be contacted separately for this topic.
Open Data download options
With the implementation of IFS Cycle 50r1 and AIFS v2, there was a significant increase in requests for Open and Free Data from ECMWF. While usage quickly returned to normal, we remind users that those data are also available from any of these alternative sources:
Note that ECMWF Open and Free Datasets are free of charge and governed by the Creative Commons CC-4.0-BY licence.
PRC freeze period ended
From 30 April 2026, a freeze period was in place for the Product Requirements Catalogue (PRC) until models' upgrade implementation. The PRC is now available again.
Users can browse, calculate costs and arrange a Service Agreement for ECMWF data. For more information, see the documentation.
Pre-schedule delivery updates after IFS Cycle 50r1 implementation
With the implementation of model upgrade, we updated the production chain to incorporate new parameters and observations. This has increased the overall model run time and the subsequent processing required to generate individual products, which in turn affects the availability timing of pre-scheduled products. We are continuing to refine and tune the system.
We apologise for any inconvenience this may cause, and please be aware that, in general, the timing of pre-scheduling is not guaranteed. Users are reminded that reports of delays should only be raised 15 minutes after the scheduled time has passed.
More information about pre-schedule delivery can be found here.
Upcoming changes to interfaces
ECMWF has implemented an updated ECPDS user interface. Many of you will have seen this during the past few weeks as an optional test interface. ECMWF Data Support Team are working on updating all documentation and support information.
Additionally, the current Product Requirements Catalogue (PRC Shopping Cart) and Product Requirements Editor (PREd) will be merged into a single unified app. This new application will include revised workflows to enable you to handle your own contact access to services, handle your own renewals, as well as the existing features of both applications. We plan to launch a test version of this application in early July, and we invite users who would like to evaluate the new interface to contact us for early access.
Upcoming migration to GRIB2 data format
To give users an update on the progress and timeline, we have organised a session at the Using ECMWF's Forecasts Event (UEF2026) next week on Thursday, 4 June 2026 at 10:30 – 11:20 CEST (09:30 – 10:20 BST). This session will be broadcast online, so you can follow along as well!
No need to fully register to follow the session. You can watch as a guest from the following link: https://ecmwfevents.com/i/using-ecmwf-s-forecasts-uef2026/login
More information and the full programme can be found here.
Further information, including where to find the data and a detailed description of the static sample dataset and parameter changes, can be found in the Migration to GRIB edition 2 - Information page.
If you have any issues, concerns or feedback, we encourage you to contact us via the ECMWF Support Portal.
Best wishes,
ECMWF Data Support Team
European Centre for Medium-Range Weather Forecasts
Reading, UK | Bologna, Italy | Bonn, Germany
ECMWF Support Portal | ecmwf.int
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