WindBorne Systems is a California-based start-up founded by Stanford graduates who originally met through a student space organisation.
The company maintains a fleet of approximately 600 long-duration weather balloons, which collect meteorological data from remote locations including polar regions, open oceans and areas lacking traditional weather stations.
WindBorne has developed a waterproof balloon design that allows the craft to land in the ocean and function as a floating buoy once its flight ends.
As a buoy, the balloon continues transmitting data, including water temperature, ocean pressure and wave height.
The company argues that surface-level data of this kind is especially valuable for forecasting, since the atmosphere and the ocean are tightly coupled systems that influence each other constantly.
A balloon that stayed up for nearly a year
One specific balloon, named "Elder", achieved a flight duration of 345 days and travelled more than 300,000 kilometres before it came down.
That longevity followed an engineering redesign of a valve that had previously leaked at extremely low temperatures, a fix that significantly extended how long the balloons could remain airborne.
Flying straight into hurricanes
WindBorne intentionally flies balloons directly into hurricanes to collect data, even though doing so destroys the balloons in the process.
The company says this approach is significantly more cost-effective than using crewed aircraft, which have traditionally been used to gather data from inside storm systems.
Feeding an AI weather model
The data collected by the balloons feeds into WeatherMesh, an AI-based weather forecasting model that the company trained from scratch, rather than adapting from an existing system.
According to findings from the National Oceanic and Atmospheric Administration, the data WindBorne provides improves the accuracy of hurricane track forecasts by 10% to 20%.
Scaling up fast
The company has set a goal of expanding its fleet to 4,000 balloons within the next 18 months, a roughly sevenfold increase from its current numbers.
Reaching that scale would give WindBorne a far denser network of atmospheric and ocean data points feeding its forecasting model, at a moment when improving hurricane prediction has taken on growing urgency amid increasingly severe storm seasons.