WindBorne Systems · 2026-06-01 · major
WindBorne WeatherMesh-6 — AI Weather Model Cuts Ensemble-Mean RMSE Up to 38% vs ECMWF, Produces Hourly 3 km Forecasts From a 128-Member Ensemble in Latent Space
WindBorne Systems shipped WeatherMesh-6, a foundation model for global weather that runs a 128-member ensemble in latent space, beats ECMWF IFS on RMSE up to 38%, and refreshes a 3 km regional forecast every hour.
An AI weather model that beats ECMWF's flagship physics forecast by up to 38% on ensemble RMSE — and refreshes hourly.
Key specs
| Rmse vs ifs | up to -38% ensemble-mean |
|---|---|
| Rmse vs aifs | up to -32% |
| Ensemble members | 128 |
| Resolution | 0.25° global, 3 km regional |
| Refresh cadence | hourly |
| Evaluation window | Jul 2025 – Mar 2026 |
| Balloons in network | ~400 |
| Launch sites | 15 |
What is it?
WeatherMesh-6 (WM-6) is the sixth generation of WindBorne's AI weather foundation model. It outputs 24 new surface, soil, and atmospheric variables plus 5 upper-air parameters at 25 pressure levels — what WindBorne says is the largest output catalog of any AI weather model so far. A separate 3 km variant covers the US and Europe at high resolution and pushes regional forecasts out to 72 hours.
How does it work?
WM-6 runs a 128-member ensemble inside the model's latent space rather than re-running an expensive physics integration per member, so each member stays at full resolution and remains physically coherent. The data-assimilation stack ingests 11 observation types — including two new satellite instruments, AMSR2 and CrIS — and WindBorne's own Global Sounding Balloon observations, encoded by their innovation against the model's prior. The model is evaluated on July 2025 through March 2026 against ECMWF IFS and AIFS as baselines.
Why does it matter?
WeatherMesh-6 turns AI from a near-term challenger into the leader on medium-range skill: WindBorne reports up to 38% lower ensemble-mean RMSE than ECMWF IFS and up to 32% lower than AIFS, with 2-meter temperature forecasts at 4.5 days as accurate as IFS's 1-day forecasts. For energy traders, emergency managers, and aviation, hourly updates and 128-member ensembles at this skill level mean tighter probabilistic planning windows than any operational forecast on offer today.
Who is it for?
operational meteorologists, energy and commodity traders, emergency managers, aviation
Try it
https://windbornesystems.com/products/forecasts