then more local news at 6:00. we will see you then. good night! on this sunday night -- high alert. severe weather breaking out right now from the plains to the great lakes. >> wow! look at the rotation! >> damaging winds, tornadoes and flooding. tonight why close to half the u.s. population could be at risk from dangerous storms before it is over. collision course. dramatic new images of a commuter train crash just moments after impact amore than 100,000 in the northeast brace for what could and nightmare commute. state of mind. the new guidelines to help mental health professionals diagnosis disorders. but some of them are causing controversy and concern. voice of experience. the president tells graduates to set an example and points to his own struggles as a man of color. and -- jackpot. more than half a billion dollars

and tonight someone has the winning powerball ticket. from a tiny town in florida that waits for the winner to claim the prize. >> from nbc news world headquarters in new york, this is "nbc nightly news" with lester holt. good evening. as we start here tonight, dangerous storms are breaking out across a wide swath of the country from oklahoma into kansas, on up into minnesota. severe thunderstorm warnings and tornado watches are up in at least six states tonight. in oklahoma city, an ominous wall cloud appeared late this afternoon as all eyes turned to the threatening skies amid a flurry of warnings. already there had been a number of tornadoes that have touched down in oklahoma, including this one we saw a bit earlier in edmond. this has been a topsy-turvy weekend for a lot of people in the country's midsection and

this dangerous weather system is on the move. tonight the national weather service says 148 million people are at risk for severe weather from now into tuesday. that's half the u.s. population. we watched as this all unfolded in oklahoma just moments ago. take a listen. >> go left! >> big-gun tornado coming down! whoa, whoa, whoa. stay on the street. >> folks, look at that. that's violent. that's violent. >> violent tornado! off to the right. big-time debris cloud. there is large structural debris. >> it's going to be heading for -- >> right in front of us! >> dobbs road. >> it's very dangerous! >> baseball-sized hail. that is approaching dobbs road. one mile south of waterloo road. you folks in rural areas up there, this is a life threatening, damaging tornado here. it is large and multi-vortex. >> as they reported in oklahoma a short while ago, our team is in place to cover it all, including nbc's janet shamlian in oklahoma city who spent some

time herself taking shelter today. janet? >> yeah, that's right, lester. the power lines are still down from last night's storm and here we go again. conditions have gotten worse very quickly here. just within the last hour we heard the tornado sirens multiple times. as you indicated, for the while we were in the back after target store about 100 yards from where i am standing with several dozen other people taking shelter. the pictures are very dramatic, and a lot of people watched this unfold live on the weather channel. >> we got a tornado, guys. >> we got a tornado? >> got a tornado on the ground right now, guys. >> there is some large debris in the air right here. >> here had comes. holy smokes. >> reporter: heavy rains, whipping winds an tornadoes pummeling the central plains. >> oh! lightning bolt. >> this one was on top of the weather channel's tornado hunt team. >> we are almost right under the tornado at this point. we can hear the roar. it is right over us but we can still see in contact with the ground farther off toward the northeast.

>> reporter: across the region tonight, more than 30 million people are in the path of the storms. in oklahoma city, 70-mile-an-hour winds took down block after block of power lines. >> we have more storms coming in tonight. they're going to be severe so we would like to get this up and make sure it is in place before another storm comes through. >> reporter: 2013 had been one of the quietest tornado seasons on record due to a cold spring. but that ended with last week's assault on texas where six people died in granbury near ft. worth. >> we have one of our stronger upper air disturbances from the spring that's come in from the pacific northwest, pushed its way southeast and now it is gathering up some of that gulf of mexico moisture. we have winds from the southeast that are moist and warm, winds aloft from the southwest. so the turning of those winds allows the storms to develop rotation. we call them super cell thunderstorms and those are the ones that produce lots of dangerous tornadoes. >> reporter: by an early count,

some 22 tornadoes saturday. 19 in kansas, three in nebraska. all within two hours. residents are aware tonight and monday could be even worse. >> i probably drive back close to oklahoma city and just stay in that underground parking garage for a while. i just don't take chances with tornadoes. >> reporter: and no one should, authorities say. a tornado also touched down in wichita tonight but no reports of injuries. there is a clearing now but lester, we're told the very worst of this storm could be still to come tonight and into tomorrow. back to you. >> janet shamlian, hang in there, thanks. weather channel meteorologist kelly cass is tracking the storms. kelly, what areas are on alert? >> we still have a high tornado threat as we go late into the evening tonight, all across the upper midwest, stretching on down towards oklahoma. take a look at the tornado watches from go from wisconsin as well as the twin cities, down into tulsa. and we also are concerned about some large hail. we already had reports of softball-sized hail. active tornado warnings. we've been following them around

the oklahoma city area, stretching on up into kansas, warnings galore. we're also looking at flash flooding in a lot of the slow-moving thunderstorms as well. tonight the red zone. minneapolis to kansas city, right on down towards tulsa and oklahoma city. tornadoes are likely. they could be large and long-lived, that means lasting for miles on the ground. and then tomorrow still more severe weather from oklahoma city on up towards chicago. so even more people will be included in those warnings. back to you. >> it's going to be a long night. kelly cass, thanks. remind folks the weather channel is covering this online and on cable. now for the train derail that snarled traffic into the northeast corridor. the ntsb continued its investigation today as tense of thousands of passengers brace for a difficult commute tomorrow. nbc's michelle franzen is in bridgeport, connecticut for us tonight. >> reporter: a new video posted on youtube captures the frantic moments after friday's train collision in bridgeport, connecticut.

>> step over this. >> reporter: shocked passengers making their way to safety just moments after impact. nbc news has not authenticated the video. today crews separated more than a dozen rail cars at the collision site and heavily damaged train cars were moved. a slow tow to a nearby rail yard. the ntsb is focusing on two sections of track with signs of possible fractures. they were sent to the agency's lab in washington, d.c. for analysis. investigators say data recorder show the trains were traveling around 70 miles per hour at the time of the collision. >> they were going 70 miles per hour just prior to the impact. >> reporter: the accident occurred in an area under long-term construction where only two of the four tracks were operational. >> we don't know the cause yet. but certainly, it is a wake-up call for paying attention to the quality and efficiency of our rail system. >> reporter: it is also near the site of a train wreck in 1911.

industry experts say the northeast corridor is the busiest train route in the country. a 457-mile stretch from washington, d.c. to boston. in connecticut alone, about 125,000 passengers travel per day through the area where the derailment occurred. about 30,000 people use the stations where service is closed. and officials will be providing shuttle buses for those 30,000 residents and are also encouraging them to take alternative transportation and car pooling. meantime, repairs on those damaged tracks has already begun. lester? >> michelle franzen tonight, thank you. after a turbulent week for the obama administration, the white house went on the defensive today. though the president himself steered clear of the controversies. nbc's peter alexander has the latest. >> obama, obama! >> reporter: with the president addressing graduates at the historically black morehouse college in atlanta today, no mention of the convergence of

controversies still brewing in washington. still, the white house is aggressively responding, calling accusations of mismanagement offensive and absurd. on the irs issue -- >> there is no question that republicans are trying to make political hay here. >> reporter: a senior advisor speaking out on all five sunday morning talk shows. >> when they want to do when lacking a positive agenda is try to drag washington into a swamp of partisan fishing expeditions trumped up hearings and false allegations. we're not going to let that happen. >> reporter: president obama's team promising accountability at the irs. still, republicans aren't satisfied. >> there is a culture of intimidation throughout the administration. it is no wonder that the agents and the irs sort of get the message. the president demonizes his opponents. >> reporter: but gop leaders concede there is no evidence the white house ordered the targeting of conservatives. >> we don't have anything to say that the president knew about this. >> the investigation has just begun so i'm not going to reach a conclusion about what we may

find. >> reporter: after what may have been among the toughest weeks of the obama presidency, a just-released poll shows the president's approval rating largely unaffected. still the majority of americans view all three issues as very important to the nation. despite white house claims that some congressional republicans are overplaying their hand. >> this is not watergate, but there are some people in the administration who have acted as if they want to be nixonian. and that's a very big problem. >> what unites all these things, it undermines the credibility of the administration and the president and the competence of government. this is a time when we have a president who is really trying hard to prove that government can improve our lives. >> reporter: at an event this afternoon, president obama complained that partisan battles are keeping this country's economy from getting stronger. lester, there are more battles on tap this week. former irs commissioner doug schulman is scheduled to testify before congress wednesday. >> all right, peter. thank you.

we now know where but we still don't know who. we're talking of course about the huge powerball jackpot and that one winning ticket that someone bought in a small town in central florida. nbc's kerry sanders is there tonight. >> reporter: in zephyrhills, florida, population 13,337, we know who didn't win. >> warren connelly from zephyrhills. >> reporter: a loser? >> a loser. >> reporter: the one and only winning ticket was sold at this publix grocery store. the chances of winning -- 1 in 175 million. >> wow. i should have went to publix. >> reporter: while it is believed a resident of this town famous for zephyrhills springs bottled water is the winner, it's possible the ticket holder could have parachuted in from elsewhere. tens of thousands come to zephyrhills for its drop zone, one of the most popular sky diving spots in the united states. annemarie hammond bought a

powerball ticket at that publix grocery store last night. >> this morning when we heard the thing on the news -- i ran to my purse. i was like -- aw. >> reporter: the winning ticket is worth $590.5 million. $148 million goes right to the federal government in taxes. if the winner takes the lump sum, it will be a $370 million payday. the second largest lottery winnings in the united states, ever. >> tonight we had the biggest jackpot in powerball history. >> reporter: the $590 million jackpot is so large, it could fund the city of zephyrhills' entire government budget for the next 12 years. >> i don't see how one person could ever spend that kind of money. in them, their children and their grandchildren couldn't spend that kind of money. >> reporter: while we're here waiting to find out who won the powerball, in virginia and new jersey, there were two winning tickets sold in the mega millions. the identities of those winning

tickets owners are yet to come forward. but by comparison to the $590 million in the powerball, the mega million winners are going to have to split a measly $190 million. lester? >> tough times indeed, kerry sanders, thanks very much. you may feel like you need a lottery jackpot when you hear the latest news at the pump. aaa says the cost of a gallon of gas has jumped 14 cents from a month ago. the average price of a gallon of regular is now $3.65. prices are highest in minneapolis and lowest in tucson. off alaska's mainland tonight, the pavlov volcano continues to erupt billowing ash 22,000 feet high. scientists tracking the volcano in alaska's remote aleutian islands chain say its steam and ash plum is thinning and is no longer a threat to international air traffic. when "nbc nightly news" continues for this sunday, new diagnosis guidelines for mental health professionals causing controversy. and later, a time honored tradition and why the old machines are once again the right stuff.

from the fda tonight -- a warning to health care providers about sterile products made by a leading compounding pharmacy. the government says the products made by the dallas-based nuvision pharmacy may have been contaminated and could put patients at rick of infection. we turn now to mental health and new guidelines to help professionals diagnose some common disorders. nbc's chief medical editor dr. nancy snyderman says for some the new classifications are causing controversy. >> reporter: at 5 years old, scott finkelstein was diagnosed with asperger's syndrome. now, 23, he's lived with the disorder for as long as he can remember. >> it just makes me unable to

read people. >> reporter: people with asperger's like scott have often relied on assistance from health services and early intervention, received because of their diagnosis. many families worry this critical aid will be in jeopardy after the release of a new handbook. >> it is a very scary thing for us and for families who have children on the autism spectrum that need services. >> reporter: that handbook, the diagnostic and statistical manual of mental disorders, or the dsm, is the gold standard used by psychiatrists for more than 60 years to guide them when diagnosing mental disorders. >> there is considerable amount of research and clinical expertise and advances that made it very appropriate for us to issue a dsm-5. >> reporter: under the new guidelines, those who had once been diagnosed with asperger's now fall under the broader umbrella of autism spectrum disorder. new diagnoses, such as hoarding disorder and binge eating

disorder have also been added to the manual. changes that have created controversy. >> dsm-5 has been too innovative allowing too many openings for unintended consequences that will lead to excessive and harmful treatment. >> reporter: despite the debate, some experts say that while disorder classification will change, treatment options will remain the same. so does the new dsm give docs more freedom to just say it i'll just fix it with a pill? >> no. the new manual doesn't give that kind of permission to fix it with a pill at all. it is not a treatment document. never was. it's a communication document. >> maybe we can think about it differently. >> reporter: a bright spot for families like the finklesteins, trying to make sure loved ones with mental disorders get the necessary care. >> just because it's gone away in the book doesn't mean it is going away in real life. >> reporter: no matter how those disorders are defined. dr. nancy snyderman, nbc news, new york.

in just a moment, a voice of experience. the president speaking personally about race and responsibility.

at his commencement speech at morehouse college in atlanta today, president obama paid tribute to the alma mater of the reverend dr. martin luther king jr. the president spoke in very personal terms tying dr. king's journey to his own struggles growing up. >> we know that too many young men in our community continue to make bad choices and i have to say, growing up, i made quite a few myself. sometimes i wrote off my own failings as just another example of the world trying to keep a black man down. i had a tendency sometimes to make excuses for me not doing the right thing. but one of the things that all of you have learned over the last four years is there's no longer any room for excuses. be the best husband to your

wife, or your boyfriend or your partner. be the best father you can be to your children. because nothing's more important. whatever success i have achieved, whatever positions of leadership i have held, have depended less on ivy league degrees or s.a.t. scores or gpas and have instead been due to that sense of connection and empathy. the special obligation i felt as a black man, like you, to help those who need it most, people who didn't have the opportunities that i had. because there but for the grace of god go i, i might have been in their shoes. i might have been in prison. i might have been unemployed. i might not have been able to support a family. and that motivates me. >> the president is sharing in a way we rarely hear him at morehouse college today.

"saturday night live" said farewell to some of its signature stars last night on a night of swan songs. bill hader made his final appearance as the nightclub stefan. seth meyers announced he's leaving the show when he takes over "late night" here on nbc. >> goodnight! >> fred armisen also reported leaving. he performed last night as the punk rocker ian rubbish. big shoes to fill when the show starts its 39th season in september. when we come back, why typewriters are suddenly hip again.

seems like everything these days is digital. and so a story about communicating in a simpler way from a simpler time almost makes us feel sentimental. nbc's stephanie gosk now on the return of the typewriter. >> reporter: not that long ago, this was the sound of the workplace. the age of the typewriter. the brand names had gravitas. smith corona. royal standard. and the oiled blickensderfer. as great as they were, these marvels of mechanics stood no chance against the digital age, or did they? at the mesa typewriter exchange in arizona, their repairman bill wald is noticing a change. >> now people using typewriters are a different group, and they love their typewriters. in the last few years i've had more and more interest from

younger people. >> reporter: not far from their english teacher has his opportunities write entirely on typewriters. >> it helps you concentrate more. because on a computer, there is other distractions. >> reporter: there's no backspace, auto correct or spell-check. >> you got to know what you're going to say, you got to make sure it makes sense. >> reporter: this classroom is home to dozens of machines. >> 20 years ago if you were collecting a typewriter, you were a town eccentric. now you can find people across the country interested in the same hobby. >> reporter: they're popping up in unlikely places. there are the famous collectors, the high-profile users, and the modern-day enthusiasts, like this group in new york taking part in a type-in. an idea started by mike that's spread around the world. tell me what it is about typewriters that you like so much. >> one, they're finely crafted. two, they're not meant to be obsolete. three, they only do one thing. >> reporter: they type. that's it. with a little practice, this is so easy. i was ready for the speed contest. >> go. >> where's the 1?

a rough start. i'm already losing. a lot harder than it looks. oh, i ripped it! but i did finish. college freshman matthew sedoni was the fastest. that's his copy on the left and mine on the right. >> when you're sitting at one you almost feel like you could be ernest hemmingway or something. >> reporter: a revival of the typewriter, proving its timeless appeal. stephanie gosk, nbc news, new york. and that's "nbc nightly news" for this sunday. brian williams will be here tomorrow. i'm lester holt reporting from new york. for all of us here at nbc news, goodnight.

i'm diane dwyer. right now firefighters are battling a fire fight. there is a preschool near by. witnesses they huge plumes of smoke are filling the air and the fire department tweeted that homes are threatened. >> tonight, reports of another significant problem for the new eastern span of the bay