Last November, NASA and its European partners launched the Sentinel-6B satellite to improve hurricane forecasts, help protect infrastructure, and benefit commercial industries, including shipping. The satellite now is flying 30 seconds behind its predecessor, Sentinel-6 Michael Freilich. Both satellites are providing precise sea level height measurements during what oceanographers expect to be a historic El Niño, a naturally occurring oceanic phenomenon in which warmer-than-usual Pacific waters shift global weather patterns.

The two satellites make up the Copernicus Sentinel-6/Jason-CS (Continuity of Service) mission, the latest in a series of ocean-observing radar altimetry missions that have been monitoring Earth’s changing seas continuously since the early 1990s.

The data each satellite is collecting will not only allow scientists to better understand this year’s El Niño but will also help them create more accurate hurricane predictions.

“This El Niño was a late-bloomer,” said Josh Willis, Sentinel-6B’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “It didn’t kick off until the middle of the year and is just now reaching a strength similar to what we’ve seen in the satellite record during significant El Niños in 1997 and 2015. We expect it to be big, and it’s already having big impacts.”

El Niños generally scramble weather patterns tied to rainfall and storms, including hurricanes. They also redistribute heat in the ocean, which affects sea level. Normally, Earth’s warmest ocean waters sit along the equator in the western Pacific. During El Niño, weakened winds, which usually blow westward along the equator, result in heat spreading east toward South America. The change in ocean heat shifts hurricane activity from the Atlantic to the Pacific Ocean.

Predicting hurricane strength

On July 15, Sentinel-6B began delivering low-latency data to scientists that could be used for weather predictions. That data will take some time to work its way into the research models on which meteorologists and climate scientists rely, but when it does, those improved models could save lives.

Data from Sentinel-6 satellite missions feeds into hurricane tracking algorithms used by federal and state agencies. Those predictions can activate disaster response efforts, mobilizing resources ranging from sandbag placement to National Guard activation. They also can lead to evacuation orders that require quick but well-informed decisions about logistics at a local level. More severe events may require engaging larger organizations, such as the Federal Emergency Management Agency.

A tropical storm can take a week or more to become a hurricane and make its way to a coastline, but a hurricane can rapidly intensify in the 48 hours prior to landfall, leaving planners little time to prepare.

“Hurricanes have been known to speed up quickly at the last moment, so the window in which to decide what to do is short,” said Deirdre Byrne, an oceanographer and altimetry expert with the National Oceanic and Atmospheric Administration (NOAA). “The goal is to forecast how much and how rapidly intensification will happen so that officials can make the right calls.”

Byrne oversees one of the country’s most crucial hurricane forecasting algorithms, NOAA’s Satellite Ocean Heat Content Suite, which has been operating since 2012.

Each Sentinel-6 satellite measures ocean height, as well as the size of waves and marine wind speed, using a radar altimeter, which bounces thousands of radar pulses a second off the crests and troughs of waves. Ocean height varies from place to place and provides insight into the ocean’s heat content, since warm water expands. That, in turn, helps forecast how fast hurricanes will grow.

The satellites each carry a second instrument, called the Global Navigation Satellite System – Radio Occultation (GNSS-RO), which measures atmospheric properties, such as humidity, pressure, and temperature.

Among the measurements Sentinel-6 is gathering, Byrne is most anticipating the ocean height data, which she plans to begin incorporating into the current Satellite Ocean Heat Content Suite algorithm by the end of the year.

“In terms of data quality, the Sentinel-6 missions are unparalleled,” Byrne said.

Together, the missions are also extending a precise dataset deep into its fourth decade. This record of sea level observations traces back to the TOPEX/Poseidon mission, which launched in 1992, and continues through to the present day with Sentinel-6 Michael Freilich. Sentinel-6B will take over for its predecessor as the reference satellite for global sea level measurements later this year.

“The key is consistency, measuring the same way, every time,” said Severine Fournier, Sentinel-6B deputy project scientist, JPL. “That’s what lets us predict hurricanes, and, in turn, protect coastal communities and infrastructure.”

More about Sentinel-6B

Sentinel-6 Michael Freilich, named after a former director of NASA’s Earth Science Division, is one of two satellites that compose the Copernicus Sentinel-6/Jason-CS mission.

Sentinel-6/Jason-CS, a part of the European Union’s Earth observation program called Copernicus, was jointly developed by ESA (European Space Agency), EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), NASA, and NOAA, with funding support from the European Commission and technical support on performance from the French space agency CNES (Centre National d’Études Spatiales). Spacecraft monitoring and control, as well as the processing of all the altimeter science data, is carried out by EUMETSAT on behalf of the European Union’s Copernicus Programme, with the support of all partner agencies.

NASA JPL, a division of Caltech in Pasadena, contributed three science instruments for each Sentinel-6 satellite: the Advanced Microwave Radiometer, the GNSS-RO, and the Laser Retroreflector Array. NASA also contributed launch services, ground systems supporting operation of the agency’s science instruments, the science data processors for two of these instruments, and support for the United States members of the international Ocean Surface Topography Science Team.

For more about Sentinel-6B, visit:

https://science.nasa.gov/mission/sentinel-6B

-end-

Media Contacts

Andrew Good / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433 / 626-379-6874
andrew.c.good@jpl.nasa.gov / andrew.wang@jpl.nasa.gov

2026-060

The post How 2 US, European Satellites Are Studying Hurricanes During El Niño appeared first on NASA Science.

Last November, NASA and its European partners launched the Sentinel-6B satellite to improve hurricane forecasts, help protect infrastructure, and benefit commercial industries, including shipping. The satellite now is flying 30 seconds behind its predecessor, Sentinel-6 Michael Freilich. Both satellites are providing precise sea level height measurements during what oceanographers expect to be a historic El Niño, a naturally occurring oceanic phenomenon in which warmer-than-usual Pacific waters shift global weather patterns.

The two satellites make up the Copernicus Sentinel-6/Jason-CS (Continuity of Service) mission, the latest in a series of ocean-observing radar altimetry missions that have been monitoring Earth’s changing seas continuously since the early 1990s.

The data each satellite is collecting will not only allow scientists to better understand this year’s El Niño but will also help them create more accurate hurricane predictions.

“This El Niño was a late-bloomer,” said Josh Willis, Sentinel-6B’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “It didn’t kick off until the middle of the year and is just now reaching a strength similar to what we’ve seen in the satellite record during significant El Niños in 1997 and 2015. We expect it to be big, and it’s already having big impacts.”

El Niños generally scramble weather patterns tied to rainfall and storms, including hurricanes. They also redistribute heat in the ocean, which affects sea level. Normally, Earth’s warmest ocean waters sit along the equator in the western Pacific. During El Niño, weakened winds, which usually blow westward along the equator, result in heat spreading east toward South America. The change in ocean heat shifts hurricane activity from the Atlantic to the Pacific Ocean.

Predicting hurricane strength

On July 15, Sentinel-6B began delivering low-latency data to scientists that could be used for weather predictions. That data will take some time to work its way into the research models on which meteorologists and climate scientists rely, but when it does, those improved models could save lives.

Data from Sentinel-6 satellite missions feeds into hurricane tracking algorithms used by federal and state agencies. Those predictions can activate disaster response efforts, mobilizing resources ranging from sandbag placement to National Guard activation. They also can lead to evacuation orders that require quick but well-informed decisions about logistics at a local level. More severe events may require engaging larger organizations, such as the Federal Emergency Management Agency.

A tropical storm can take a week or more to become a hurricane and make its way to a coastline, but a hurricane can rapidly intensify in the 48 hours prior to landfall, leaving planners little time to prepare.

“Hurricanes have been known to speed up quickly at the last moment, so the window in which to decide what to do is short,” said Deirdre Byrne, an oceanographer and altimetry expert with the National Oceanic and Atmospheric Administration (NOAA). “The goal is to forecast how much and how rapidly intensification will happen so that officials can make the right calls.”

Byrne oversees one of the country’s most crucial hurricane forecasting algorithms, NOAA’s Satellite Ocean Heat Content Suite, which has been operating since 2012.

Each Sentinel-6 satellite measures ocean height, as well as the size of waves and marine wind speed, using a radar altimeter, which bounces thousands of radar pulses a second off the crests and troughs of waves. Ocean height varies from place to place and provides insight into the ocean’s heat content, since warm water expands. That, in turn, helps forecast how fast hurricanes will grow.

The satellites each carry a second instrument, called the Global Navigation Satellite System – Radio Occultation (GNSS-RO), which measures atmospheric properties, such as humidity, pressure, and temperature.

Among the measurements Sentinel-6 is gathering, Byrne is most anticipating the ocean height data, which she plans to begin incorporating into the current Satellite Ocean Heat Content Suite algorithm by the end of the year.

“In terms of data quality, the Sentinel-6 missions are unparalleled,” Byrne said.

Together, the missions are also extending a precise dataset deep into its fourth decade. This record of sea level observations traces back to the TOPEX/Poseidon mission, which launched in 1992, and continues through to the present day with Sentinel-6 Michael Freilich. Sentinel-6B will take over for its predecessor as the reference satellite for global sea level measurements later this year.

“The key is consistency, measuring the same way, every time,” said Severine Fournier, Sentinel-6B deputy project scientist, JPL. “That’s what lets us predict hurricanes, and, in turn, protect coastal communities and infrastructure.”

More about Sentinel-6B

Sentinel-6 Michael Freilich, named after a former director of NASA’s Earth Science Division, is one of two satellites that compose the Copernicus Sentinel-6/Jason-CS mission.

Sentinel-6/Jason-CS, a part of the European Union’s Earth observation program called Copernicus, was jointly developed by ESA (European Space Agency), EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), NASA, and NOAA, with funding support from the European Commission and technical support on performance from the French space agency CNES (Centre National d’Études Spatiales). Spacecraft monitoring and control, as well as the processing of all the altimeter science data, is carried out by EUMETSAT on behalf of the European Union’s Copernicus Programme, with the support of all partner agencies.

NASA JPL, a division of Caltech in Pasadena, contributed three science instruments for each Sentinel-6 satellite: the Advanced Microwave Radiometer, the GNSS-RO, and the Laser Retroreflector Array. NASA also contributed launch services, ground systems supporting operation of the agency’s science instruments, the science data processors for two of these instruments, and support for the United States members of the international Ocean Surface Topography Science Team.

For more about Sentinel-6B, visit:

https://science.nasa.gov/mission/sentinel-6B

-end-

Media Contacts

Andrew Good / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433 / 626-379-6874
andrew.c.good@jpl.nasa.gov / andrew.wang@jpl.nasa.gov

2026-060

In early July 2026, for the second time in three months, a powerful typhoon crossed the U.S. Northern Mariana Islands and Guam in the North Pacific Ocean. Super Typhoon Bavi was at peak intensity when it neared the islands on the night of July 5, bringing winds of 290 kilometers (180 miles) per hour, along with torrential rain and dangerous storm surge.

This nighttime image, captured by the VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 satellite, shows Bavi’s eye at about 15:30 Universal Time on July 5 (1:30 a.m. local time on July 6). Light from the Moon, which was in the waning gibbous phase, illuminates the eyewall’s western side. The eye passed over Rota, north of Guam, several hours after the image was acquired.

Bavi became a super typhoon in the early hours of July 4 local time while tracking west over the warm ocean. Satellite observations indicated that sea surface temperatures were around 30 degrees Celsius (86 degrees Fahrenheit) in the region. Bavi was the third tropical cyclone in 2026 to reach category 5 intensity on the Saffir-Simpson wind scale.

The typhoon caused extensive damage across Guam, Rota, and Saipan, according to news reports, downing power poles and lines; flooding roads and littering them with debris; and damaging buildings, including a water distribution station on Rota. U.S. Coast Guard crews worked to clear navigation hazards in the waterways around Guam and the Northern Marianas and reopen ports as dangerous marine conditions subsided, according to reports. This damage comes on top of destructive winds and flooding from Super Typhoon Sinlaku, which crossed the islands in mid-April.

On July 8, Bavi remained a powerful typhoon as it moved west over the Philippine Sea. In the early afternoon, when the image above was captured, the National Weather Service reported maximum sustained wind speeds of 250 kilometers (155 miles) per hour. Forecasts indicated the typhoon’s track could bend northwest toward Taiwan, the Ryukyu Islands of southern Japan, and mainland China and weaken over the next several days.

Writing in Yale Climate Connections, meteorologist Jeff Masters said that Bavi is the type of storm that might be expected when a strong El Niño event is building, which is currently the case. El Niño-year typhoons may form farther east, giving them more time over warm water to intensify before curving toward Asia, Masters explained, “resulting in a greater chance of reaching Category 5 intensity.”

NASA Earth Observatory images by Michala Garrison, using data from NASA EOSDIS LANCE, GIBS/Worldview, and the Joint Polar Satellite System (JPSS), and hurricane track data from the U.S. Naval Research Laboratory. Story by Lindsey Doermann.

References & Resources

• CIMSS Satellite Blog (2026, July 3) Super Typhoon Bavi rapidly intensifies to a Category 5 storm east of Guam, eventually passing just north of the island of Rota. Accessed July 8, 2026.
• Military.com (2026, July 7) Coast Guard Works to Reopen Guam, CNMI Ports After Super Typhoon Bavi. Accessed July 8, 2026.
• NASA Earth Observatory (2026, April 14) Super Typhoon Sinlaku. Accessed July 8, 2026.
• National Weather Service (2026, July 8) Public Tropical Cyclone Advisory. Accessed July 8, 2026.
• Weather Underground (2026, July 8) Super Typhoon Bavi. Accessed July 8, 2026.
• Yale Climate Connections (2026, July 3) Super Typhoon Bavi becomes the 3rd Cat 5 of 2026. Accessed July 8, 2026.