[Fredricka Whitfield, Cnn Anchor:] Hello, again, everyone. I'm Fredricka Whitfield. Here are the top stories we're following in the CNN NEWSROOM. More than 94 million Americans are on the move this holiday weekend and so is a brutal winter storm. It's coating parts of the Midwest in ice and snow and across the south, tornados are the big threat. What you need to know before heading home for Christmas. And U.S. troops come under fire while trying to evacuate Americans from South Sudan. We're learning more about the attack and the conditions of the injured service members. And making a critical repair 220 miles from earth, NASA astronauts are doing that right now. We'll show you live pictures of the spacewalk and tell you why their work is vital to the future of the ISS. First up, that dangerous system that is barreling across the U.S. right now, it's threatening multiple states with snow, ice even tornadoes and it's hitting on the same weekend that tens of millions of Americans are heading home for the holidays. In the south, tornadoes are rare in December, but right now, it's the biggest threat. And that risk became a reality last night in Mississippi. A twister touched down there levelling trees, but so far no injuries have been reported. And in the Midwest, snow and ice are creating treacherous conditions on the road and forcing airlines to cancel and even delay flights. Our Nick Valencia is in the icy city of Kansas City, Missouri. So Nick, just how bad are conditions there?
[Nick Valencia, Cnn Correspondent:] Just in the last few minutes, Fred, it started to sleet pretty steadily here. It's about 23 degrees, but feels much colder, more like 13 degrees. You could see sleets sort of collecting here on top of our camera case. A lot of the country's midsection is really going to see some severe weather this weekend. It's going to make the brunt of the severe weather is going to hit the midsection.
[Valencia:] From cars skidding on frozen roads and some flipping over to flight delays at the nation's airports and expected power outages, it is beginning to look a lot like a holiday travel nightmare.
[Nancy White, Aaa:] It could, indeed, be the perfect storm with an increase in travelers and an increase in the amount of distance travelers are going.
[Valencia:] Here is the wild forecast, ice storm warnings in Oklahoma, severe thunderstorms and possible tornadoes across the south and heavy snow and flooding in the nation's midsection. Who is going to be impacted, more than 94 million Americans traveling this week, already dangerous driving conditions this morning in Kansas and Iowa.
[Unidentified Male:] Just tried to stop. I couldn't. My car went out.
[Valencia:] If you are flying, watch out for possible flight cancellations in the Midwest and up to two-hour delays in Kansas City, Chicago and Dallas with more delays expected up the east coast on Sunday. Travel experts say it is best to check ahead before leaving home.
[Unidentified Female:] We really recommend that travelers be smart. Plan ahead. Take advantage of smartphone technology by keeping up to date on travel and road conditions.
[Valencia:] And while the weather can be a pain for millions around the nation, for some football fans in Green Bay, Wisconsin, it is providing a $10 an hour job for sweeping Lambeau Field for Sunday's game.
[Unidentified Male:] You get the chance to get out and meet people, and get some good exercise and enjoy the cold.
[Valencia:] And we just checked win the airlines, Fred. No cancellations or delays just yet, but conditions here are expected to worsen throughout the afternoon. We're expecting freezing rain and snow. So, bundle up out there.
[Whitfield:] Yes, but like that last gentleman said, enjoy the cold, Nick. Are you enjoying the cold?
[Valencia:] Yes. I'll try. It's really cold out here for California. I'm progressively adding more and more layers. It will be OK, though.
[Whitfield:] Keep adding those layers. You're making it look really easy. Thanks, Nick, appreciate it. Let's go now to the CNN Weather Center where Jennifer Grey is keeping an eye on the dangerous storm system. We laugh, but it is potentially dangerous.
[Jennifer Gray, Ams Meteorologist:] Yes, it really is especially the severe component to it. This is going to be affecting millions especially people in the south. It's not something on the top of their mind as they're heading out doing Christmas shopping, but they may have a tornado threat this afternoon. So it is something you really don't want to let your guard down. We do have the ice, as well. That's stretching from Oklahoma all the way through Missouri and even portions of Illinois. The tornado watch, though, has been issued this morning and this goes into effect until 6 p.m. Central Time and this affects places like Shreveport, Alexandria, Lake Charles even Beaumont and Houston you're in this, as well. We're already seeing some pretty strong storms starting to fire up. We have actually seen some severe thunderstorm watches, as well. Here's where the severe threat is. We have a slight risk stretching anywhere from Houston all the way to Pensacola, pretty much. That stretches up into portions of Ohio. The moderate risk is more centered around the Arklatex and that heads into Jackson, Memphis, Nashville, you're included in this, as well. We could see isolated tornados, damaging winds, as well. So as we track the storm system late this evening, it is going to be right around Memphis, Jackson, Little Rock, you'll see the showers and storms a little earlier, as well and then just continuing to track to the east as we go through the overnight hours. Atlanta, we could see some pretty strong showers and storms during the overnight hours tonight into tomorrow, as well, and then it just sort of sets up along the east coast. This is mainly a rain event. We have seen a lot of winter storms already this year, but this is mainly a rain event. The reason is, very warm air has been pumping into the southeast and over the east coast. Washington, D.C. has already set a record for today and they set that around 11:00 this morning.
[Whitfield:] A warm record?
[Gray:] Yes, a record.
[Whitfield:] Wow, my goodness.
[Gray:] Very warm. They were around 62 degrees at 11:00 and the record was 61.
[Whitfield:] Wow, OK, well, something tells me people were very excited about hitting the malls then. That means no icy roads are standing in the way of them getting in that last shopping weekend at least in the mid-Atlantic. Thanks so much, Jennifer, appreciate that. All right, now, to this developing story out of Africa. A U.S. aircraft in South Sudan came under heavy gun fire this morning during a mission to evacuate American civilians. Four service members are injured. The country has been in turmoil since the president accused the former vice president of attempting a coup last week and a lot of people had been killed in the clashes since then. Pentagon correspondent, Barbara Starr joins me now from Washington. So Barbara, this was was this like an attempted evacuation, not necessarily a rescue mission, but just to lift many of these Americans out of this hard to get place in Sudan?
[Barbara Starr, Cnn Pentagon Correspondent:] That's right, Fred. About 30 Americans or so are in this town of Bur in Southern Sudan. We're told mainly working for the United Nations. Here's what happened. Three U.S. military aircraft were trying to land at the airfield and they were going to evacuate these Americans. There is no other way for them to get out of this area right now because of the violence, because of the ongoing war that has erupted in this region. So, they start to approach the airfield. They are flying low and slow on that final approach and they come under fire. Three V-22 aircraft flown by U.S. troops took gunfire. One of the aircraft we are told was seriously damaged, possibly with a fuel leak. Four U.S. troops wounded by this gunfire from the ground, thankfully, all three aircraft made it back t to Uganda. The wounded were flown onto Kenya where they are getting military getting medical care. But make no mistake this is a very serious situation because those Americans that they were trying to get out of there, they are still there. So, the military now reassessing, we are told, how to go back in there, how to evacuate these American citizens out of this region. The feeling is that the American aircraft were definitely targeted mainly perhaps, perhaps by the rebel forces in the region. This is a town that just fell to the rebels a day or so ago. So, this is a very tense situation.
[Whitfield:] Indeed it is. All right, Barbara Starr, thanks so much. Let's find out more on how this is shaping up on the ground there in Sudan. In fact, Secretary of State John Kerry is sending a special envoy to South Sudan. Let's find out if that would make a difference in any way. Nima Elbagir from Khartoum, Sudan right now. So, what is next realistically?
[Nima Elbagir, Cnn Correspondent:] Well, as you said, not being called a rescue mission yet. But that does not belie the seriousness of this situation a second town slightly further south from there also falling to the rebels. This isn't one unified rebel faction. This is a number of different groupings that seem it be taking the opportunity that's been posed by the recent disarray in the past few days. The concern has always been with South Sudan. Was there enough infrastructure, to stand independent of North Sudan and the U.S. at the time believes very much, yes, there was some very definite champions. Susan Rice, former ambassador to the U.N. was one of them and she put out a very emotional message on Friday, she is someone who has been very much at the forefront of the U.S. very close relationship with South Sudan. This is a relationship that has spanned the entire 21-year civil war between north and south. She is calling to choose peace. She says that they have their independence. They should try and keep their country together. But at the moment, no one is particularly hopeful. We don't even really have a sense of how many people have died on the ground. Even aid agencies don't really know. The U.N. says they believe it could be between 500 and 600 people. This is a very, very tense situation and the attempted evacuations. Aide workers saying that's not going to help the situation, the civilians on the ground Fredricka.
[Whitfield:] All right, Nima, thanks so much. Keep us posted on that situation there, very tense. All right, back in this country now, four people have been arrested in connection with a deadly carjacking at a New Jersey mall. A man was killed last Sunday after shopping with his wife when he was allegedly confronted by the suspects with a gun. Alexandra Field is following this case for us out of Newark, New Jersey. So Alexandra, what is the latest now?
[Alexandra Field, Cnn Correspondent:] Well, this morning, Fred, prosecutors are saying that all four men are being charged with murder and carjacking. It was a busy night for investigators. Overnight they made four arrests both in New Jersey and Pennsylvania. These arrests come less than a week after Dustin Freidland, a 30-year-old attorney from Hoboken, New Jersey, was shot and killed outside a New Jersey shopping mall. Police say that the suspects were after his silver Range Rover. Prosecutors spoke this morning saying that carjackings reached epidemic levels here in Essex County, New Jersey, a couple of years ago since then law enforcement officials have been fighting to try to stop the problem.
[Paul Fishman, U.s. Attorney:] You have the right to be safe and the expectation that you should be safe in this county in the state of New Jersey. And, in particular, you shouldn't have to worry that wherever you go, whether it's in downtown Newark or the Short Hills Mall or anywhere else that someone would put a gun to your head and take your car.
[Field:] The four suspects are all between the ages of 29 and 33. Along with murder and carjacking charges, they also face weapons charges. If convicted of all charges, they face a maximum sentence of life in prison and, Fred, each of the four men are being held on $2 million bail.
[Whitfield:] And what more was revealed, if anything, by investigators about the weapon or how this went from a carjacking to a shooting. What words may have been exchanged, any more details?
[Field:] Sure, Fred. What we know is that Freidland had just finished shopping at the mall with his wife. We are told that he had helped her into the passenger seat, opening the car door for her. Investigators believed that after that he walked around the back of the car and believe there may have been some sort of struggle before shots were fired. His wife jumped out of the car. Two of the suspects then took off that car. Police say the other two suspects took off in another and at this time, investigators say they have not recovered the murder weapon.
[Whitfield:] So sad. All right, Alexandra Field, thanks so much. All right, way up in space, what's it like to float weightlessly and be a repairman, so to speak, at the same time. We'll ask someone who has actually done that, quite a few times, next.