An unusually brutal winter storm is set to pummel more than 160 million Americans from Friday, as a stretched “polar vortex” sends a devastating blast of Arctic air, bringing heavy snows and freezing rains.Winter Storm Fern is forecast to engulf an area well over half the length of the continental United States, stretching from Texas and the Great Plains region to the mid-Atlantic and northeastern states.Scientists say the increasing frequency of such disruptions of the polar vortex may be linked to climate change, though the debate is not yet settled and natural variability also plays a role.– What is the polar vortex? –The polar vortex is a large region of cold, low-pressure air that circulates counterclockwise high above the Arctic, in the stratosphere some 10 to 50 kilometers (six to 30 miles) above Earth’s surface.In a typical winter, it forms a relatively compact, circular system that helps lock in the coldest air to high northern latitudes.”Usually the vortex spins merrily along and has little effect on our weather, but occasionally it moves or stretches southward over North America, bringing with it a jolt of cold,” Jennifer Francis, a senior scientist at the Woodwell Climate Research Center, told AFP.– What happens when it stretches? -At times, big atmospheric waves that form closer to the ground can travel upward and knock the polar vortex out of whack.Rather than completely breaking down — as happens during dramatic “sudden stratospheric warming” events — the vortex can stretch out into a more oval shape.”Think of it like a rubber band being pulled,” Judah Cohen, a climate dynamics scientist at MIT, told AFP.”That allows the cold air to expand much further south, like we’re like we’re seeing this week here in the United States.”Jason Furtado, a meterologist at the University of Oklahoma whose research focuses on long-range forecasting, said these stretching events aren’t as long-lasting as complete breakdowns, but are significant nonetheless, especially for North America.-Is it linked to climate change? –This is where the science becomes more debated.There is broad agreement — reflected in assessments by the UN’s climate science body — that the Arctic is warming much faster than the global average, through a process known as Arctic amplification, and human-caused climate change is behind it. Cohen argues that this uneven warming helps amplify large atmospheric waves over Eurasia, which in turn makes the polar vortex spill more frequently over North America.”Studies suggest these aberrations in the vortex are happening more often in a warming world, which favors more frequent winter extremes,” said Francis.Furtado said observations from the past 20 years do show an increase in such events, but he cautioned against drawing strong long-term conclusions tying them directly to human-caused climate change.”In my opinion, it’s harder to make that connection going out much further, simply because I think we just don’t have enough data.”

Photographs of fresh bruising on Donald Trump’s hand raised eyebrows on Thursday, but the 79-year-old US president dismissed renewed speculation over his health, saying he had simply hit a table.Trump has been seen with frequent bruising on his right hand since returning to the White House last year, often concealing it with bandages and makeup.The White House has said it is due to a combination of frequent handshaking and the aspirin he takes for his cardiovascular health, which can lead to proneness for bruising.However, photos on Thursday at the World Economic Forum in Davos, Switzerland showed dark bruises in a similar location — but this time on Trump’s left hand.The images, taken while Trump was at an inaugural ceremony for his global “Board of Peace” initiative, quickly spread on social media.”I clipped it on the table,” Trump told journalists on Air Force One when asked about the bruising, adding: “I would say, take aspirin if you like your heart, but don’t take aspirin if you don’t want to have a little bruising.”The White House had earlier downplayed any concerns, giving the same explanation for the bruise.Photos from early in the “Board of Peace” event and yesterday show no bruising on the left hand.Speculation has swirled about Trump’s fitness given his age — he is the oldest person to take office as president — the hand bruising, swelling in his legs, and several apparent moments of dozing off during public events.The administration disclosed last summer that Trump’s leg swelling had been diagnosed as a symptom of chronic venous insufficiency — a common condition in which faulty vein valves allow blood to pool, causing swelling, cramping and skin changes.It can be managed with medication or targeted procedures.An unannounced hospital visit last year added to suspicions of secrecy around his health.Weeks afterward, Trump’s doctor said MRI imaging had shown the president to be in “excellent” cardiovascular health.

New York City has sued to block a TV show about the police department fronted by celebrity psychologist Dr. Phil that local officials say is “extremely problematic.”In a lawsuit filed Wednesday, the city argues episodes of “Behind the Badge,” which was given the green light by former mayor Eric Adams, “pose an imminent threat to the life and safety of active NYPD officers.” “For example, the faces, voices, and names of undercover officers conducting operations in plainclothes are not obscured,” the complaint alleges.”There are numerous other pieces of harmful footage that cannot be released to the public. For example, the identities of individuals in NYPD custody are depicted in the rough cuts without any blurring or redactions applied to their faces.”The city, now led by Democratic mayor Zohran Mamdani, is asking the court to prohibit the sale, distribution, or broadcast of the material, which a New York State Supreme Court judge temporarily granted on Wednesday.”The  Production  company is disappointed that this lawsuit was filed without advance notice and an opportunity to respond to the request for a restraint on publication which the United States Constitution prohibits,” said Chip Babcock, a lawyer for the TV show.Dr. Phil is the stage name of Phil McGraw, who was made famous to daytime television audiences by Oprah Winfrey, who had him on her show, and went on to host his own long-running series as a tough-talking psychologist. Since his eponymous show was dropped from the network television, the 75-year-old has transitioned to other reality television ventures for his own channel.Mamdani has sought to chart a starkly different course from his predecessor Adams, a flamboyant former police captain known for his idiosyncratic style and love of publicity.On Friday, a judge will hold a hearing on the documentary that is produced by TV talkshow host Dr. Phil’s son Jordan McGraw and his production company McGraw Media, court filings showed.

The White House’s X account on Thursday posted a doctored photo of a protester arrested in Minnesota, showing her face contorted with tears without disclosing that the photorealistic image had been altered.The edited photo of Nekima Levy Armstrong — among three people arrested for allegedly disturbing a church service while protesting an immigration crackdown — illustrates how President Donald Trump’s administration is increasingly using deepfakes or AI imagery to make political arguments.On Thursday morning, Secretary of Homeland Security Kristi Noem posted an image on X showing Armstrong’s arrest, her face calm and expressionless.About 30 minutes later, the White House posted the same image on the platform, but altered to show Armstrong sobbing, her mouth open, forehead wrinkled, and tears streaming down her face.A caption superimposed on the image read “ARRESTED,” labeling Armstrong a “far-left agitator.”The White House post offered no disclaimer that the image had been edited, and it was not immediately clear whether the alteration was done using an AI tool or other photo editing software.When reached for comment, the White House redirected AFP to a post on X by White House Deputy Communications Director Kaelan Dorr, who tacitly acknowledged that the image had been modified.”YET AGAIN to the people who feel the need to reflexively defend perpetrators of heinous crimes in our country I share with you this message,” Dorr wrote on X, resharing the White House post featuring Armstrong’s altered photo.”Enforcement of the law will continue. The memes will continue. Thank you for your attention to this matter.”Underneath the White House post, several users questioned why the image had been altered to make Armstrong appear to be crying.”We should be disturbed by any party using AI to manipulate photographs and presenting them as fact, which appears to be the case here,” one user wrote. “This point of view should have bipartisan agreement.”- ‘Lack of decorum’ -In the age of deepfakes and AI, such edited images are now “commonplace in partisan politics,” said Walter Scheirer of the University of Notre Dame.”They are frequently used to humiliate opposition figures or make exaggerated political statements that resonate with a political base,” Scheirer told AFP.”One could consider this the contemporary version of newspaper political cartoons, but there is a notable lack of decorum when it comes through official government communication channels.”During the first year of his second White House term, Trump ramped up his use of hyper-realistic but fabricated visuals on Truth Social and other platforms, often glorifying himself while lampooning his critics.Trump or the White House have similarly shared AI-made images depicting the president dressed as the pope, roaring alongside a lion, and conducting an orchestra at the Kennedy Center — Washington’s premier arts complex — where he installed himself as chair of the board.Underscoring the strategy’s potential appeal to younger voters, similar AI-driven messaging has also been adopted by other arms of the Trump administration as well as by some of the president’s political rivals.