WindBorne Systems

WindBorne Systems designs, builds and operates a global constellation of long-duration smart weather balloons, collecting atmospheric data with proprietary hardware, flight autonomy software and AI weather forecasting. Founded in 2019 by a team of Stanford engineers and headquartered in Redwood Shores, California, the company takes a vertically integrated approach to a gap in atmospheric observation: 85% of the atmosphere remains effectively unobserved, and traditional radiosondes cannot reach remote oceans or extreme environments.

For those working on forecasting and autonomous systems, the relevant artefacts are WeatherMesh and the flight stack behind the balloons. WeatherMesh is WindBorne's AI-based medium-range global forecast model, which the company claims is the most accurate of its kind, surpassing Google DeepMind's GraphCast and ECMWF's physics-based models. Flight autonomy software governs a network of balloons that steer themselves for more than 40 days at a time; the flagship Global Sounding Balloon (GSB) weighs just 1.2 kg and gathers atmospheric profiles from anywhere on Earth. The Atlas constellation is described as the world's largest balloon network.

The company reports that its approach yields 10x more data per dollar over land and 150x more over oceans than traditional radiosondes. Customers and users span government and defence, including NOAA, the U.S. Navy and the U.S. Air Force, as well as energy trading, utilities and meteorology. The GSB was named one of TIME's Best Inventions of 2025.