There were five separate topic-oriented breakout groups in the User Voice Corner session at UEF 2026. Notes of the exchanges that took place are provided below, under the five topic headings.
1. "New ECMWF Model Versions: 50r1 and AIFS V2s"
Q1Q: What is the difference between AIFS-Single and AIFS-ENS Control member?
Single is unperturbed, based on minimising an RMSE metric. AIFS-ENS Control is based on a different error (CRPS) minimization metric, and an unperturbed analysis, but has random "diffusion" perturbations applied during the run; it is therefore much less like a typical Control run, in the classical sense.
Q2Q: Precipitation has improved with this cycle because now convective precip is moving. There are still some unrealistic bullseye blobs; is it possible that they will now move?
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And yes, the bullseye blobs may now move.
Q3Q. I loved the explanation for the difference between AIFS Single and AIFS ENS Control. It is difficult to be in a position where all these new models are published, and we struggle using all of this in our operational service. But we have to take a leap of faith on when to start using it in our operations. We are struggling to describe to our colleagues how to use it, when to use it, what the advantages of it are and when not to use it. Forecasters are just pushing products, we don't always have time to look at everything. Often we look at local model outputs and compare to IFS. The AIFS is just another (global) model. My question is, how do we get to learn it as forecasters. What's the main focus points we need to be aware of as forecasters.
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Noted. To help with this we could learn not just from analyses but also from short range forecasts (which we already do for precipitation).
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2. "Extreme / Interesting Case Studies"
Extreme cases reported
A representative from the World Energy and Meteorology Council (UEA, Norwich) raised the issue of extreme cold events, especially how well these can be predicted when they are linked to broader weather types, and asked if there was any verification for weather regime forecasts.*1,*2,*3
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*6) https://confluence.ecmwf.int/display/FUG/Section+8.1.11+Potential+vorticity+charts
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3. "How would you like to see ECMWF products evolve in future"
Overview:
The meeting focused on gathering feedback on ECMWF products, with particular emphasis on AI-based models, visualisation challenges, and user workflow efficiency. Participants discussed future directions for product development and how to better support operational forecasters.
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The discussion highlighted a shift from data provision towards intelligent, user-centric products. Key priorities include improving explainability of AI models, reducing data overload through better summarisation and guidance, and developing flexible tools that align with real forecasting workflows.
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4. "Land Surface Processes and 2m Temperature"
Introductions & Roles:
- Participants introduced themselves, representing research, forecasting, technical, and agricultural sectors from various countries. Key areas included surface observations, turbulence and boundary layer physics, land surface modeling, snow/ice/glacier processes, and operational forecasting.
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