Latest news with #NEXRAD
Scientific American
30-05-2025
- Climate
- Scientific American
Inside the Lifesaving Power of Doppler Weather Radar
Outside every National Weather Service (NWS) office around the U.S. stands what looks like an enormous white soccer ball, perched atop metal scaffolding several stories high. These somewhat plain spheres look as ho-hum as a town water tower, but tucked inside each is one of modern meteorology's most revolutionary and lifesaving tools: Doppler radar. The national network of 160 high-resolution radars, installed in 1988 and updated in 2012, sends out microwave pulses that bounce off raindrops or other precipitation to help forecasters see what is falling and how much—providing crucial early information about events ranging from flash floods to blizzards. And the network is especially irreplaceable when it comes to spotting tornadoes; it has substantially lengthened warning times and reduced deaths. Doppler radar has 'really revolutionized how we've been able to issue warnings,' says Ryan Hanrahan, chief meteorologist of the NBC Connecticut StormTracker team. But now meteorologists and emergency managers are increasingly worried about what might happen if any of these radars go offline, whether because of cuts to the NWS made by the Trump administration or threats from groups that espouse conspiracy theories about the radars being used to control the weather. 'Losing radar capabilities would 'take us back in time by four decades,' says Jana Houser, a tornado researcher at the Ohio State University. If they go down, 'there's no way we're going to be effective at storm warnings.' On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. How Doppler radars work The NWS installations form a network called the Next Generation Weather Radar, or NEXRAD. Inside each giant white sphere is a device that looks like a larger version of a home satellite TV dish, with a transmitter that emits pulses in the microwave region of the electromagnetic spectrum. Those pulses bounce off raindrops, snowflakes, hailstones—what meteorologists collectively call hydrometeors—and back to the dish antenna. (The pulses also sometimes bounce off bats, birds and even moving trains, which yield characteristic radar patterns that experts can usually identify.) The power of the returning signals lets experts create a picture of size, shape and intensity of any precipitation—and this is what you see on a phone app's radar map or a TV broadcast. But NEXRAD can do much, much more than show how hard it's raining. Within its sphere, each unit rotates and scans up and down through the sky, helping forecasters see what is happening at multiple levels of a storm system. These vertical profiles can show, for example, whether a tornado is forming or a storm is creating a downburst—a rapid downward blast of wind. 'Doppler radar basically allows us to see in the clouds,' Hanrahan says. And then there's the 'Doppler' part itself. The name refers to a phenomenon that's familiar to many, thanks to the electromagnetic waves' acoustic counterpart. We've all experienced this, often most obviously when we hear an emergency vehicle siren pass nearby: the pitch increases as the car gets closer and decreases as it moves away. Similarly, the returning radar bounce from a rain droplet or piece of tornadic debris that is moving toward the emitter will have a shorter wavelength than the pulse that was sent out, and the signal from an object moving away from the radar will have a longer wavelength. This allows the radar to efficiently distinguish the tight circulation of a tornado. The nation's radar system was upgraded in 2012 to include what is called dual polarization. This means the signal has both vertically and horizontally oriented wavelengths, providing information about precipitation in more than one dimension. 'A drizzle droplet is almost perfectly spherical, so it returns the same amount of power in the horizontal and in the vertical,' Hanrahan says, whereas giant drops look almost like 'hamburger buns' and so send back more power in the horizontal than the vertical. Are Doppler radars dangerous? Can they affect the weather? Doppler radars do not pose any danger to people, wildlife or structures—and they cannot affect the weather. Along the electromagnetic spectrum, it is the portions with shorter wavelengths such as gamma rays and ultraviolet radiation that can readily damage the human body—because their wavelengths are the right size to interact with and damage DNA or our cells. Doppler radars emit pulses in wavelengths about the size of a baseball. Being hit by extremely concentrated microwave radiation could be harmful; this is why microwave ovens have mesh screens that keep the rays from escaping. Similarly, you wouldn't want to stand directly in front of a radar microwave beam. Military radar technicians found this out years ago when working on radars under operation, University of California, Los Angeles, climate scientist Daniel Swain said during one of his regular YouTube talks. They 'had experiences like the candy bar in their pocket instantly melting and then feeling their skin getting really hot,' he said. Similar to how a microwave oven works, when the microwave signal from a radar hits a hydrometeor, the water molecules vibrate and so generate heat because of friction and reradiate some of the received energy, says Cynthia Fay, who serves as a focal point for the National Weather Service's Radar Operations Center. But 'microwave radiation is really not very powerful, and the whole point is that if you stand more than a couple dozen feet away from the dome it's not even really going to affect your body, let alone the global atmosphere,' Swain adds. At the radar's antenna, the average power is about 23.5 megawatts (MW) of energy, Fay says. (A weak or moderate thunderstorm may generate about 18 MW in about an hour.) But the energy from the radar signal dissipates very rapidly with distance: at just one kilometer from the radar, the power is 0.0000019 MW, and at the radar's maximum range of 460 kilometers, it is 8.8 x 10 –12 MW, Fay says. 'Once you're miles away, it's just really not a dangerous amount' of energy, Swain said in his video. And Doppler radars spend most of their time listening for returns. According to the NWS, for every hour of operation, a radar may spend as little as seven seconds sending out pulses. The idea that Doppler radar can control or affect the weather is 'a long-standing conspiracy [theory] that has existed really for decades but has kind of accelerated in recent years,' Swain said in his video. It has resurfaced recently with threats to the National Oceanic and Atmospheric Administration radar system from an antigovernment militia group, as first reported by CNN. The Washington Post reported that the group's founder said that its members were carrying out ' attack simulations ' on sites in order to later destroy the radars,—which the group believes are 'weather weapons,' according to an internal NOAA e-mail. NOAA has advised radar technicians at the NWS's offices to exercise caution and work in teams when going out to service radars—and to notify local law enforcement of any suspicious activity. 'NOAA is aware of recent threats against NEXRAD weather radar sites and is working with local and other authorities in monitoring the situation closely,' wrote a NWS spokesperson in response to a request for comment from Scientific American. What happens if weather radars go offline? NOAA's radars have been on duty for 24 hours a day, seven days a week and 365 days a year since 1988 (with brief downtimes for maintenance and upgrades). 'It's amazing what workhorses these radars have been,' Hanrahan says. But they do require that periodic maintenance because of all the large moving parts needed to operate them. And with Trump administration cuts to NOAA staffing and freezes on some spending, 'we just got rid of a lot of the radar maintenance technicians, and we got rid of the budget to repair a lot of these sites,' Swain said in his video. 'Most of these are functioning fine right now. The question is: What happens once they go down, once they need a repair?' It is this outage possibility that most worries weather experts, particularly if the breakdowns occur during any kind of severe weather. 'Radars are key instruments in issuing tornado warnings,' the Ohio State University's Houser says. 'If a radar goes down, we're basically down as to what the larger picture is.' And for much of the country—particularly in the West—there is little to no overlap in the areas that each radar covers, meaning other sites would not be able to step in if a neighboring radar is out. Hanrahan says the information provided by the radars is irreplaceable, and the 2012 upgrades mean 'we don't even need to have eyes on a tornado now to know that it's happening. It's something that I think we take for granted now.'
Yahoo
14-05-2025
- Climate
- Yahoo
Phased Array: The next generation of weather radar is here
The current network of weather radars in the United States was installed in the late 1980s and into the 1990s. There are nearly 160 weather radars in the network. The radars are the NEXRAD WSR-88D Weather Surveillance Doppler Radars. Radar was first put to use in World War II. Doppler radar technology came about in the 1960s and gained traction as the next big thing for radars in the 1970s. While some private companies were the first to provide Doppler radar to portions of the public, the National Weather Service began building the current weather radar network in 1988. Since then, the radars have undergone countless updates and modifications, but the time is getting near to retire the 30+ year-old network and find a reliable replacement. That's where phased array radar comes in. Phased array radar is the latest technology in radar development. The technology has been around for just over 20 years, but some significant advancements have taken shape over the past few years. Unlike the mechanical WSR-88D radars, phased array radars are fully digital and 'steer' the radar beam electronically. The new radars can scan the skies in roughly 1 minute. That is a huge advancement from the current 5 to 8 minute scan time for the WSR-88D. To put it in perspective, the phased array radars can scan the skies up to 8 times in the time it takes the WSR-88D radars to make a single scan. This will be highly beneficial during severe weather when every second counts. Less time between scans translates into better and more timely warnings. Phased array radars also have the ability for the user (i.e., National Weather Service) to direct the radar beam where they want it to go. This, too, translates to faster scan time during severe weather. If storms are coming from the west and the sky is quiet in the east, then eliminating the need to scan the clear skies to the east will save time. Today, phased array radar has two disadvantages compared to the WSR-88D. First, the new technology is expensive compared to the WSR-88D radars. Second, the radar azimuth, which is the horizontal angular distance from true north, is currently at 120°. The current WSR-88D radar, meanwhile, has an azimuth range of 360°, a full circle. Still, this will get us as close to real-time radar data as we've ever seen. Phased array radar technology is still in the research stage, and no timeline has been announced as to when we might see the new radar approved and installed into a national network. The current NEXRAD WSR-88D network is scheduled to stay in operation through 2035. Time will tell if phased array radar will replace the legacy radar system at that time. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Yahoo
14-05-2025
- Climate
- Yahoo
Anti-government group threatens key US weather radar sites
CHICAGO (NewsNation) — Officials from the National Weather Service are on alert after an anti-government group publicly made threats against radar installations across the country. Known as NEXRAD sites, or Next Generation Weather Radar, they are essential tools for meteorologists to monitor and forecast severe weather. Extremist group Veterans on Patrol claims NEXRAD installations contain military-operated 'weather weapons' that are 'poisoning the skies.' The group has not detailed how it intends to target the sites, but its founder, Michael 'Lewis Arthur' Meyer, publicly posted a response to the Washington Post on the messaging app Telegram. FAA, Duffy face grilling over safety, delays at major US airports Meyer said the group plans to 'take as many NexRads offline as possible.' He added that he has 'full authority' to do so. In response, the National Oceanic and Atmospheric Administration, which oversees the NWS, issued an internal warning advising employees to stay vigilant and to report any suspicious activity to law enforcement. 'NOAA is aware of recent threats against NEXRAD weather radar sites and is working with other authorities in monitoring the situation closely,' a spokesperson told NewsNation. The Southern Poverty Law Center has classified Veterans on Patrol as an anti-government militia. The group has claimed it is watching radar sites in several states and is allegedly exploring ways to disable the equipment. These developments come at a challenging time for the National Weather Service, which has been operating under severe staffing shortages. Roughly one-third of its positions remain unfilled following a wave of layoffs initiated by the Trump administration's Department of Government Efficiency. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Engadget
09-05-2025
- Business
- Engadget
The Morning After: What we learned from the FTC v. Meta antitrust trial (so far)
Years after the Federal Trade Commission sued Meta in a bid to halt acquisitions of Instagram and WhatsApp, the trial that will shape its future is finally underway. The trial kicked off last month when CEO Mark Zuckerberg took the stand, and it's expected to last several weeks. Facebook's 2012 acquisition of Instagram is a central part of the FTC's case against Meta. The government says Zuckerberg bought Instagram to neutralize it as a competitor. When Instagram's cofounder and former CEO Kevin Systrom took the stand, he didn't exactly defend the move. While Zuckerberg had testified Meta had helped Instagram grow, Systrom testified Zuckerberg saw Instagram as a 'threat' to Facebook's growth and intentionally withheld company resources. Further still, Facebook's decision to pay $1 billion for Instagram — an app with no revenue and just a handful of employees — seemed like an incredible sum. Sheryl Sandberg thought Zuckerberg had overpaid for Instagram. In an exchange between the two from 2012, she said, 'Yes, of course it's way too much.' There are more nuggets, too. Like how Meta sees TikTok as an earnest threat, how Europeans aren't buying the ad-free subscriptions (duh), and why Zuckerberg thought about nuking users' friend lists annually to boost engagement. Read Karissa Bell's full breakdown of the FTC v. Meta antitrust trial so far. — Mat Smith Get Engadget's newsletter delivered direct to your inbox. Subscribe right here! Samsung is ready to finally launch its slim iteration of the S25. It says it'll offer a look at 'the next evolution of Galaxy' devices and unveil 'more about the latest addition to the Galaxy S series.' Then the teaser coaxed something 'beyond slim.' So it's the S25 Edge, even if Samsung isn't saying the S25 Edge. The Unpacked event will kick off May 12 at 8PM ET. Continue reading. The National Oceanic and Atmospheric Administration has warned the National Weather Service of possible attacks from an armed conspiracy group. According to a report from CNN, the group Veterans on Patrol is going after government radars because it believes they're being used as 'weather weapons.' Despite its cooler-than-average name, the NEXRAD or Next Generation Weather Radar is fairly mundane, used by NWS to detect precipitation in the atmosphere. NEXRAD plays a vital role in locating thunderstorms and tornados. National Weather Service staff have been advised to buddy up when working at remote radar sites and report anything suspicious to the authorities. Continue reading. Google I/O 2025 should be one of the more exciting tech keynotes in recent memory. Plus, for the first time, Google has spun out a dedicated Android showcase a whole week earlier. What can we expect to see in Android 16? We've had lots of hints at an upcoming design change to the platform, reportedly called Material 3 Expressive. A leaked blog post discusses the research behind Material 3 Expressive and how the visual overhaul led to action elements standing out more and greater responsiveness on the users' part. Then there are Gemini AI updates, more Google service updates and everything else. We break down what we're expecting to see. Continue reading.
Engadget
07-05-2025
- Engadget
NOAA warns staff a militia group thinks its radars are 'weather weapons'
The National Oceanic and Atmospheric Administration has warned the National Weather Service of possible attacks from an armed conspiracy group targeting Doppler radar stations, according to a report from CNN . The group, Veterans on Patrol, is going after government radars because it believes they're being used as "weather weapons." CNN learned of the possible attacks through NOAA emails warning NWS staff that Veterans on Patrol was planning to conduct "penetration drills on NEXRAD sites to identify weaknesses," with the ultimate goal of destroying NEXRAD. Despite its cooler-than-average name, the NWS uses NEXRAD or "Next Generation Weather Radar" for a fairly mundane purpose: detecting precipitation in the atmosphere. NEXRAD plays a vital role in locating thunderstorms and tornados, making it easier to evacuate vulnerable communities before disaster strikes. It's not clear what Veterans on Patrol sees as threatening about radar — the group was previously focused on white nationalism and Pizzagate-style government conspiracies — but concern over the effects of being exposed to radio waves is a common bugbear for conspiracy-types. For example, groups set fire to cell towers early in the COVID-19 pandemic because of a belief that 5G somehow spread the virus. Viewing radar as a weapon could originate from some similar misconceptions. NWS staff have been advised to use the buddy system when working at remote radar sites and report anything suspicious to the authorities. Even without the threat of physical violence, though, the NWS and NOAA at large have already been devastated in 2025. Hundreds of weather forecasters were fired because of the cuts made by the Trump administration, just one of many attempts to dismantle government services.
