Forecasters are about to lose a vital source of satellite data just months ahead of the peak of the Atlantic hurricane season, as the Department of Defense prepares to shut down a more critical data stream than cybersecurity issues.

The data is generated by microwave sensors on three aging polar orbit satellites that serve both military and civilian functions. These sensors are crucial for hurricane forecasting, as they can analyze cloud layers and the storm’s core, providing insights even at night without relying on visible light.

Experts are concerned that this loss of data will hinder forecasters during a period when the National Weather Service is deploying fewer weather balloons due to budget cuts and insufficient meteorological staff. The absence of this data affects meteorologists’ ability to assess storm threats effectively and prepare emergency managers accordingly. Microwave data offers some of the earliest signs that wind speeds are intensifying in storms.

“It’s a tool that enables deeper insight. Losing it will significantly impair hurricane forecasts. It can detect the formation of eye walls in tropical storms, indicating whether these storms are intensifying,” an expert commented.

Researchers suggest that as ocean temperatures rise due to human-induced climate change, rapid intensification in tropical storms may become more common.

The three satellites operate through a collaborative initiative involving the Defense Weather Satellite Program, NOAA, and the Department of Defense.

While hurricane experts expressed concern about the loss of this tool, NOAA’s communications director, Kim Doster, minimized the potential impact of the National Weather Service’s decision on hurricane forecasting.

In a message, Doster described the military’s microwave data as “one dataset in a robust suite of hurricane prediction and modeling tools” within the NWS.

According to Doster, these forecasting models integrate data from various satellites located around 22,300 miles away from Earth, providing a synchronized view that follows the planet’s rotation.

They also incorporate measurements from Hurricane Hunter planes, buoys, weather balloons, land radars, and additional polar orbit satellites, including NOAA’s joint polar satellite system.

A U.S. Space Force representative confirmed that the satellites and their equipment are operational, and data will continue to be sent directly to satellite readout terminals across the DOD. However, the Navy’s Fleet Numerical Weather and Oceanography Center has opted to cease public data processing and sharing, officials reported.

The Navy did not respond promptly to requests for comments.

Earlier this week, a Navy division informed researchers that it would halt data processing and sharing by June 30. Some researchers received notifications from the Navy’s Fleet Numerical Weather and Oceanography Center regarding their reliance on outdated and insecure operating systems.

“We cannot upgrade our systems; it raises cybersecurity risks and jeopardizes our DOD network,” stated an email reviewed by NBC News.

This decision could lead to forecasters losing up to half of the available microwave data, according to McNoldy.

Additionally, this microwave data is crucial for snow and ice researchers tracking polar sea ice levels, which helps understand long-term climate patterns. Sea ice, formed from frozen seawater, expands in winter and melts in summer. Tracking sea ice is essential as it reflects sunlight back into space, cooling the planet. This metric is vital to monitor over time, especially since summer Arctic sea ice levels are showing declining trends due to global warming.

Walt Meier, a senior research scientist at the National Snow and Ice Data Center, mentioned that his program learned about the Navy’s decision earlier this week.

Meier noted the satellites and sensors have been operational for approximately 16 years. While researchers anticipated their eventual failure, they did not expect the military to abruptly discontinue data sharing with little notice.

Meier stated that the National Snow and Ice Data Center has depended on military satellites for sea ice coverage data since 1987 but will adapt by utilizing similar microwave data from Japanese satellites known as AMSR-2.

“Integrating that data into our system could take several weeks,” said Meier. “While it may not undermine the integrity of sea ice climate records, it will pose additional challenges.”

Polar orbit satellites, part of the Defense Weather Satellite Program, offer intermittent coverage of regions prone to hurricanes.

These satellites generally circle the Earth in a north-south path every 90 to 100 minutes at relatively low altitudes, according to Meier. The microwave sensors scan narrow bands of the Earth, estimated to be around 1,500 miles wide.

As the Earth rotates, these polar orbit satellites capture images that can help researchers analyze storm structure and potential strength when they are within range.

“Often, great passes provide extensive data beyond just the hurricane,” said McNoldy, who added that the loss will decrease the frequency of scans for areas covered by microwave scans and specific storms.

Hurricane modeler Andy Hazelton, an associate scientist at the University of Miami Ocean and Atmospheric Research Institute, mentioned that microwave data is still utilized in some hurricane models and by forecasters with access to real-time visualizations.

Hazelton highlighted that forecasters always look for visual cues from microwave data, which typically provides early indications of rapidly strengthening storms.

The National Hurricane Center defines rapid intensification as a 35 mph or greater increase in sustained winds in tropical storms within a 24-hour period. The loss of microwave data is particularly concerning as scientists have observed a rise in rapid intensification linked to climate change due to warmer seawater.

A 2023 scientific report indicated that tropical cyclones in the Atlantic have about a 29% higher likelihood of rapid intensification from 2001 to 2020 compared to the period from 1971 to 1990. For instance, Hurricane Milton was strengthened into a Category 5 hurricane just 36 hours after being classified as a tropical storm, with part of this intensification occurring overnight when other satellite equipment offered less information.

This trend poses significant risks, particularly when storms like Hurricane Idria intensify just before approaching the coast.

“We’ve definitely observed numerous instances of rapid intensification right before landfall recently, something we cannot afford to overlook,” McNoldy remarked.

Brian Lamare, a dedicated forecaster at the National Weather Service in Tampa Bay, noted that this data is crucial for predicting flood impacts when hurricanes make landfall.

“These scans are key for predicting the areas of heaviest rainfall and the rates of rainfall,” said Lamarre. “This data is vital for public safety.”

Hurricane season lasts from June 1 to November 30, peaking at the end of summer and early fall. NOAA forecasters anticipate a busier hurricane season in 2025, with expectations of 6-10 hurricanes.