In today's newsletter: The attack in New Orleans underscores the biggest terror threat the U.S. faces. Winter weather is forecast to take hold across most of the country. And Donald Trump will be sentenced next week in his hush money case.

Here's what to know today.

The Bourbon Street attacker in New Orleans appeared to have long been an observant but not a radical Muslim. But hours before the attack, Shamsud-Din Jabbar posted videos online professing his support for the Islamic State terrorist group — and his intent to kill strangers rather than his family and friends, as he had originally planned.

The New Year’s Day attack, which killed 14 people, underscores how extremism online and political divisions have created a “perfect storm” for radicalization in America, experts say. Finding extremist communities online has never been easier, and the threats have never been higher. But experts also say that the ideology of those carrying out attacks has never been more splintered.

According to the federal government, the main terror threat to the U.S. now is lone actors inspired by extremist ideology. The majority of attackers are on the far right, but sometimes, as in the New Orleans attack, the motivating ideology is different.

“We’re seeing more and more people sort of pick and choose their own ideology to suit their own grievances,” said John Horgan with Georgia State University. “They look to find a reason to make sense of what they have already decided to do.”

Experts agree that there is no one profile for people who commit extremist attacks and that terrorism today is more diverse than ever. Law enforcement is struggling to track the increasingly fractured threat.

Read the full story here.

More coverage of the New Orleans attack:

More details come to light about man who died in Cybertruck

The decorated Army veteran who blew up a Tesla Cybertruck at the entrance of the Trump International Hotel in Las Vegas on New Year’s Day left writings that gave insight into his movements and state of mind in the days leading up to the incident. According to Assistant Sheriff Dori Koren of the Las Vegas Metropolitan Police Department, investigators were able to access one of two phones found in the Cybertruck. It included writing in an app that seemed to serve as Matthew Alan Livelsberger’s journal, including two letters that suggested a possible motive in the blast.

In one letter, Livelsberger said the county’s leadership is “weak” and “only serves to enrich themselves.” In a second letter, Livelsberger wrote that the U.S. is “the best country” but that it’s “headed towards collapse.” The letter also said, “This was not a terrorist attack. It was a wake-up call.”

Spencer Evans, the special agent in charge of the FBI’s Las Vegas division, said Livelsberger likely had post-traumatic stress disorder and that investigators are aware that there were potential “family issues or personal grievances” that may have been contributing factors. Officials said Livelsberger, 37, died of a self-inflicted gunshot wound.

Read more on what officials revealed about Livelsberger’s writings.

In the days before New Year’s Eve, Livelsberger messaged his ex-girlfriend out of the blue. “I’m in Denver,” Livelsberger wrote to Alicia Arritt. “Are you single?”

The pair, who hadn’t been in touch since 2022, exchanged a few breezy texts, including some about the Cybertruck that would be used in the incident. It wasn’t until FBI agents showed up at Arritt’s home a few days after they first got in touch that she learned his fate. In an interview with NBC News, Arritt recalled her past relationship with Livelsberger and the struggles he faced. “I’ve just been rolling it around my head for two days,” she said. “I don’t understand it.”

Major winter storm to impact eastern two-thirds of U.S.

A major storm system is set to wallop a large swath of the country with cold temperatures and possibly heavy snow and hazardous ice, forecasters said. About 45 million people are under winter alerts from Kansas to Maryland for the storm, which will set in today and last until Monday, the National Weather Service said.

Cities such as St. Louis, Indianapolis and Cincinnati may see the worst conditions today, with snowfall amounts of 6 to 12 inches and ice accumulations of .25 to 5 inches. Tomorrow, severe storms will rumble across the South and impact 7 million people from southeast Texas to Mississippi and southern Tennessee. Monday will be a messy day in the Ohio Valley, Mid-Atlantic and the Northeast. The area south of New York City is expected to see the heaviest snowfall totals. Here’s what else we know.

Judge sets sentencing date in Trump hush money case

Donald Trump will be sentenced Jan. 10., in his hush money case, and one big detail was already made known: The president-elect won’t be jailed, fined or have to serve probation. The decision made yesterday by Judge Juan Merchan to deny Trump’s bid to dismiss the case called for “a sentence of unconditional discharge,” which would allow the conviction to stand but without imposing the aforementioned punishments. Merchan wrote in his ruling that dismissing the case would have caused “immeasurable damage” to people’s confidence in the rule of law. Trump spokesperson Steven Cheung called Merchan’s decision a violation of Supreme Court precedent.

Trump was convicted last year of falsifying business records related to a hush money payment to his then-attorney Michael Cohen paid to adult film star Stormy Daniels in 2016. He can appear in person or virtually for next Friday’s sentencing, which is scheduled four days after Congress is set to certify the November election results and 10 days before his inauguration as the 47th president.

More politics news:

Which celebrity couple finally reached a divorce settlement after eight contentious years?

A. Britney Spears and Kevin Federline
B. Angelina Jolie and Brad Pitt
C. Katie Holmes and Tom Cruise
D. Mariah Carey and Nick Cannon

Find out the answer and test your knowledge of this week's most read stories. (The answer to the question is also at the bottom of this newsletter.)

Ditching cash? Some small businesses wish you weren't

Whenever a retailer swipes your card, it costs them. That's been true for years, but since the pandemic spurred more consumers to embrace "touchless" payments, some businesses have seen a bigger bite to their margins. One hot dog seller in Westchester County, New York, told NBC News' Kayla Steinberg and Vicky Nguyen said it bakes these so-called "swipe fees" into its menu prices. And a deli in Manchester, New Hampshire, has started charging a "convenience fee" for those who don't pay with cash. Meanwhile, as Visa raises some of its swipe fees, a long-running battle on Capitol Hill over these charges spills into 2025 with no resolution in sight.

— Rich Bellis, senior business & economy editor

If you love the look of rugs but hate the effort it takes to keep them clean, a washable rug might be your perfect solution. NBC Select editors spoke to experts about the benefits of washable rugs and which brands to shop.

Thanks for reading the Morning Rundown. Today's newsletter was curated for you by Elizabeth Robinson.

By the way, the answer to the quiz question above is B. Angelina Jolie and Brad Pitt.

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