WindBorne Systems

WindBorne Systems is a weather technology company founded in 2019 and headquartered in Redwood Shores, California, with roots in the Stanford Student Space Initiative. Co-founders include CEO John Dean, Kai Marshland, and Paige Brown, all Stanford alumni who began experimenting with extended-duration weather balloons through the university's engineering program around 2015.

The company operates Atlas, which it describes as the world's largest balloon constellation for in-situ atmospheric data collection. WindBorne's smart, altitude-controlled sounding balloons can remain airborne for up to 40 days, compared to approximately two hours for conventional weather balloons. During multi-day flights, individual balloons circumnavigate the globe, collecting continuous atmospheric sounding data from the surface to the upper troposphere. The balloons gather 10 times more data per dollar over land and 150 times more data per dollar over oceans compared to conventional alternatives. WindBorne's target is to operate 10,000 balloons concurrently by 2028, delivering complete global coverage.

In addition to its data collection network, WindBorne has developed WeatherMesh, a transformer-based AI weather forecasting model. At the time of the company's Series A announcement in June 2024, WeatherMesh had surpassed Google DeepMind's GraphCast as the most accurate medium-range global weather forecast model. WindBorne sells in-situ atmospheric observation data to national meteorological agencies and commercial customers, and also sells forecasts directly produced by WeatherMesh.

The company employs approximately 89 people and is located at 1600 Bridge Pkwy, Redwood City, CA 94065. Total funding raised is approximately $24.9 million. The $15 million Series A closed in June 2024 and was led by Khosla Ventures, which also led WindBorne's pre-seed round in 2019. Other investors include Footwork VC, Pear VC, Convective Capital, and Ubiquity Ventures.

WindBorne's technology addresses a longstanding gap in global atmospheric observation, particularly over oceans and in the Southern Hemisphere, where conventional radiosonde launches are sparse. The platform serves weather forecasting agencies, climate researchers, aviation, and environmental monitoring customers.