Forecasters are set to lose some of their sharpest eyes in the sky just a few months before Atlantic hurricane season peaks when the Department of Defense halts a key source of satellite data over cybersecurity concerns.
The data comes from microwave sensors attached to three aging polar-orbiting satellites operated for both military and civilian purposes. Data from the sensors is critical to hurricane forecasters because it allows them to peer through layers of clouds and into the center of a storm, where rain and thunderstorms develop, even at night. The sensors don’t rely on visible light.
Losing the data — at a time when the National Weather Service is releasing fewer weather balloons and the agency is short on meteorologists because of budget cuts — will make it more likely that forecasters miss key developments in a hurricane, several hurricane experts said. Those changes help meteorologists determine what level of threat a storm may pose and therefore how emergency managers ought to prepare. Microwave data offers some of the earliest indications that sustained winds are strengthening inside a storm.
“It’s really the instrument that allows us to look under the hood. It’s definitely a significant loss. There’s no doubt at all hurricane forecasts will be degraded because of this,” said Brian McNoldy, a hurricane researcher and senior research associate at the University of Miami’s Rosenstiel School of Marine, Atmospheric, and Earth Science. “They’re able to detect when an eye wall forms in a tropical storm and if it’s intensifying — or rapidly intensifying.”
Researchers think rapid intensification is becoming more likely in tropical storms as the oceans warm as a result of human-caused climate change.
The three satellites are operated for both military and civilian purposes through the Defense Meteorological Satellite Program, a joint effort of the National Oceanic and Atmospheric Administration and the Department of Defense.
While hurricane experts said they were concerned about losing the tool, Kim Doster, NOAA’s communications director, downplayed the decision’s effect on hurricane forecasting by the National Weather Service.
In an email, Doster said the military’s microwave data “is a single dataset in a robust suite of hurricane forecasting and modeling tools in the NWS portfolio.”
Doster said these models include data from geostationary satellites — a different system that constantly observes Earth from about 22,300 miles away and offers a vantage point that appears fixed because the satellites synchronize with Earth’s rotation.
They also ingest measurements from Hurricane Hunter aircraft missions, buoys, weather balloons, land-based radar and from other polar-orbiting satellites, including NOAA’s Joint Polar Satellite System, which she said provides “the richest, most accurate satellite weather observations available.”
A U.S. Space Force official said the satellites and their instruments in question remain functional and that the data will be sent directly to weather satellite readout terminals across the DOD. The Navy’s Fleet Numerical Meteorology and Oceanography Center made the decision to stop processing that data and sharing it publicly, the official said.
The Navy did not immediately respond to a request for comment.
Earlier this week, a division of the Navy notified researchers that it would cease to process and share the data on or before June 30, and some researchers received an email from the Navy’s Fleet Numerical Meteorology and Oceanography Center, saying that its data storage and sharing program relied on a processing station that was using an “end-of-life” operating system with vulnerabilities.
“The operating system cannot be upgraded, poses a cybersecurity concern, and introduces risk to DoD networks,” the email, which was reviewed by NBC News, said.
The move will cut the amount of microwave data available to forecasters in half, McNoldy estimated.
This microwave data is also used by snow and ice scientists to track the extent of polar sea ice, which helps scientists understand long-term climate trends. Sea ice forms from frozen ocean water. It grows in coverage during winter months and typically melts during warmer times of the year. Sea ice reflects sunlight back into space, which cools the planet. That makes it an important metric to track over time. The extent of summer Arctic sea ice is trending lower because of global warming.
Walt Meier, a senior research scientist at the National Snow and Ice Data Center, said his program learned of the Navy’s decision earlier this week.
Meier said the satellites and sensors are about 16 years old. Researchers have been preparing for them to eventually fail, but they weren’t expecting the military to pull the plug on data with little warning, he said.
Meier said the National Snow and Ice Data Center has relied on the military satellites for data on sea ice coverage since 1987, but will adapt its systems to use similar microwave data from a Japanese satellite, called AMSR-2, instead.
“It certainly could be a few weeks before we get that data into our system,” Meier said. “I don’t think it’s going to undermine our sea ice climate data record in terms of confidence in it, but it’s going to be more challenging.”
The polar-orbiting satellites that are part of the Defense Meteorological Satellite Program provide intermittent coverage of hurricane-prone areas.
The satellites typically zip around the globe in a north-south orientation every 90-100 minutes in a relatively low orbit, Meier said. The microwave sensors scan across a narrow swath of the earth, which Meier estimated at roughly 1,500 miles.
As the Earth rotates, these polar-orbiting satellites can capture imagery that helps researchers determine the structure and potential intensity of a storm, if it happens to be in their path.
“It’s often just by luck, you’ll get a really nice pass over a hurricane,” McNoldy said, adding that the change will reduce the geographic area covered by microwave scans and the frequency of scans of a particular storm.
Andy Hazelton, a hurricane modeler and associate scientist with the University of Miami Cooperative Institute for Marine & Atmospheric Studies, said the microwave data is used in some hurricane models and also by forecasters who can access near real-time visualizations of the data.
Hazelton said forecasters are always looking for visual signatures in microwave data that often provide the first evidence a storm is rapidly intensifying and building strength.
The National Hurricane Center defines rapid intensification as a 35-mph or higher increase in sustained winds inside a tropical storm within 24 hours. Losing the microwave data is particularly important now because in recent years, scientists have observed an increase in rapid intensification, a trend likely fueled in part by climate change as ocean waters warm.
A 2023 study published the journal Scientific Reports found that tropical cyclones in the Atlantic Ocean were about 29% more likely to undergo rapid intensification from 2001 to 2020, compared to 1971 to 1990. Last year, Hurricane Milton strengthened from a tropical storm to a Category 5 hurricane in just 36 hours. Some of that increase took place overnight, when other satellite instruments offer less information.
The trend is particularly dangerous when a storm, like Hurricane Idalia, intensifies just before striking the coast.
“We’ve certainly seen in recent years many cases of rapid intensification ahead of landfall. That’s the kind of thing you really don’t want to miss,” McNoldy said, adding that microwave data is “excellent at giving the important extra 12 hours of lead time to see the inner core changes happening.”
Brian LaMarre, the former meteorologist-in-charge at the National Weather Service’s weather forecasting station in Tampa Bay, said the data is also useful for predicting flood impacts as a hurricane comes ashore.
“That scan can help predict where the heavier precipitation and rainfall rates can be,” LaMarre said. “This data is critically important to public safety.”
Hurricane season begins June 1 and ends Nov. 30. It typically starts to peak in late summer and early fall. NOAA forecasters have predicted a more busy 2025 hurricane season than typical, with six to 10 hurricanes.