In November 2025, NASA and its European partners launched the Sentinel-6B satellite to improve hurricane forecasts, help protect infrastructure, and benefit industries like shipping. This new satellite is now flying 30 seconds behind its predecessor, Sentinel-6 Michael Freilich. Both satellites are collecting highly accurate measurements of sea level height, which are especially important during what oceanographers believe is a historic El Niño event. El Niño is a natural climate pattern where warmer-than-average ocean temperatures in the Pacific shift global weather patterns, often leading to extreme weather conditions. The two satellites are part of the Copernicus Sentinel-6/Jason-CS mission, which continues a long line of satellite missions that have been monitoring Earth’s oceans since the early 1990s. These missions use radar altimetry, a technique that measures the height of the ocean surface by bouncing radar signals off the water. The data collected from both Sentinel-6B and its predecessor will help scientists better understand the current El Niño and improve hurricane predictions. “This El Niño was a late bloomer,” said Josh Willis, Sentinel-6B’s project scientist. “It didn’t start until mid-year and is only now reaching the strength seen in major El Niños in 1997 and 2015. We expect it to be significant, and it’s already causing major changes in weather patterns.” El Niño events can disrupt normal weather patterns, shifting where hurricanes form and intensify. Typically, the warmest ocean waters are found near the equator in the western Pacific, but during El Niño, these waters move eastward toward South America. This shift can move hurricane activity from the Atlantic to the Pacific, altering storm paths and intensities. Sentinel-6B has already begun sending real-time data to scientists, which can be used to improve weather forecasts. While it will take some time for this data to be fully integrated into the models used by meteorologists, the improved accuracy could help save lives by enabling better disaster preparedness. Hurricane forecasts rely on data from Sentinel-6 satellites, which feed into algorithms used by federal and state agencies to track storms and prepare for emergencies. These predictions can trigger actions like sandbag placement, National Guard mobilization, and evacuation orders. With the ability to rapidly intensify in the days before landfall, hurricanes require quick decisions by local officials. Deirdre Byrne, an oceanographer at NOAA, oversees one of the most important hurricane forecasting tools, the Satellite Ocean Heat Content Suite. She is eager to incorporate the new ocean height data from Sentinel-6B into her models, which can help predict how fast hurricanes will grow. The data from Sentinel-6 missions are considered the highest quality available, and their continuous record of sea level measurements, dating back to 1992, ensures that scientists can track long-term ocean changes and improve hurricane forecasting for years to come.