Post by @rowancheung

WindBorne Systems, a California startup founded by Stanford graduates who met through a student space group, operates roughly 600 long-duration weather balloons that gather data from open ocean, polar regions, and other areas conventional networks rarely reach. The company has now demonstrated a waterproof design that lets a balloon land at sea and keep transmitting as a floating buoy, reporting wave height, ocean pressure, and water temperature. One balloon, Elder, flew 345 days and more than 300,000 kilometers after engineers redesigned a valve that had been leaking at low temperatures. The observations feed WeatherMesh, an AI forecasting model WindBorne trained from scratch. NOAA has found the data improves hurricane track forecasts by 10 to 20 percent. The company aims to field 4,000 balloons within 18 months.