on the broadcast tonight from tampa, hurricane warnings posted in new orleans tonight, and across a wider area of the gulf, as isaac is on the move over very warm water, on schedule to arrive, seven years to the day since katrina. here in tampa, the rain delay an unconventional start to the big week for the gop, how the storm is forcing mitt romney and the party to rewrite the script for this convention. also, the risk factor, an important story tonight about breast cancer, women's health and prevention. and are you going to be allowed to use your electronics on the plane after all? there's news on that front tonight. "nightly news" begins now. captions paid for by nbc-universal television and good evening from the republican convention in tampa, and this is not the way the

republicans wanted it to be. the reason for it? our lead story tonight, the storm named isaac, growing in strength, currently on kind of an eerie course churning toward new orleans in the very warm waters to our west, so while this event has been condensed and while it's going to get off to something of a distracted start that's for good reason. think of the louisiana delegation here, they can't now get home at this point, they're huddled at their hotel, they're all katrina veterans themselves, that's the situation we begin with here tonight, so because of these two major stories, we have assembled both our weather team and our political team to cover both fronts. we begin tonight with weather channel meteorologist jim cantore in new orleans. hey, jim, good evening. >> reporter: good evening, brian. this storm all day has tried to intensify into a hurricane and it's really moments away from doing so, with 70-mile-per-hour winds. the satellite again just exhibiting this large sprawling storm through the eastern gulf of mexico which has already

caused the water to rise. there's no getting around that. over the next 24 hours that water rise pushes up toward the northern gulf coast and as you can see the track bringing the center west of new orleans, the worst possible scenario for bringing the water up the mississippi delta, and then it will crawl through southeastern louisiana potentially as a category 1 hurricane with winds at 90 miles per hour. the surge, that's the first thing we're going to have to deal with and it's not just southeast louisiana. it's mississippi. it's alabama, all the way over to the florida panhandle, 6 to 12 feet and then the rainfall which could the biggest problem of all, we're talking about 6 to 12, locally 20 inches of rain. can the pumps get 20 inches of rain out of new orleans? that's the question they're going to have to answer tonight. no question, this looks like it's going to be one of the worst blows that we've seen since katrina and possibly gustav back in 2008 and the big question at the end of the day is, will new orleans be able to keep the crescent city dry. >> all right, jim cantore starting us off from new orleans. nbc's lester holt has also made his way to that city.

lester is standing by as well. lester, good evening. >> reporter: brian, good evening. to answer jim's question, authorities here do believe the pump system will hold here. it's been upgraded. the city officials have basically said they will not be caught flat-footed as they were seven years ago by katrina. the hurricane warning center is telling folks that preparations to protect life and property should be rushed to completion. the big concern, the water, especially in those low-lying parishes to the south of new orleans that are outside the levee protection system. when word came to evacuate the east bank of plaquemines parish, wilma taylor didn't hesitate. she and her grandchildren are getting out. did you think twice? >> no, i didn't think twice. i think one time and i'm gone. >> reporter: in this parish just south of new orleans where katrina first came ashore seven years ago, cars lined up today to make the ferry crossing to the relative safety of the west bank of mississippi, heeding a mandatory evacuation order for some 7,000 parish residents.

>> they're all coming to us now, right up the river. >> reporter: parish president billy nungesser is watching the picture of what's heading their way with growing concern. >> this storm especially slowing down scares us, because that means that storm surge will beat against that levee, and that will put them very easily to fail and if they fail and open up, of course the whole community floods and we see widespread devastation, and if anyone does stay, you could see loss of life. >> reporter: sandbags and sheets of the ubiquitous plywood mark communities feeling especially vulnerable today, some drawing their own line in the sand. >> we're just going to stick it out. now we have the sandbags, that may help. >> reporter: they're doing the best they can to fortify the levee along the east bank of the mississippi here in plaquemines parish. the fact is, the math works against them. the levee stands at eight feet, they're expecting a storm surge in this area of up to 11 feet. under those circumstances it will overtop. >> we're very much protected --

>> reporter: but officials expect it will be a different story in new orleans itself and adjacent jefferson parish. isaac will be the first major test of a $14 billion makeover of the system that failed the city so disastrously in 2005. >> the levees have been raised to a higher level of protection, pumping stations have been fortified. >> reporter: as long as isaac remains below a category 3, new orleans itself is not under a mandatory evacuation. >> i want to assure you all that there is nothing that this storm is going to bring us that we do not believe that we are prepared to handle. >> reporter: but it is more than lisa haywood is prepared to handle. >> i have faith in god. i don't have faith in those walls. >> reporter: she lost her lower ninth ward home to katrina and only returned a year ago to a place where it seems time forgot. now, she's evacuating again. >> here we go again. i wonder if i'm going to actually lose my home again and have to start all over. >> reporter: from here in louisiana to alabama, national

guard units are being called up to be able to respond to emergencies once the storm arrives. shelters are being put in place as well, prepared to handle 5,000 people in shelters here in louisiana, and we should mention, brian, if and when they would have to evacuate new orleans, not likely, but if they happen, there would be no shelters of last resort, no convention center, no superdome. >> lester holt along the mississippi in new orleans for us tonight, lester, thanks. we're also joined live by a man we just saw in lester's story, the mayor of the city of new orleans, mitch landrieu. mr. mayor, been watching you on television all day, we know how busy you are. regarding the lack of those shelters of last resort, and we all know what happened inside many of them last time the airport convention center superdome, will you have enough especially for the people we saw get impacted by katrina last time? >> brian, we believe that we do. one of the things that we really

had to get much better at is making sure that all of the citizens had a plan and what we're seeing now is people have really prepared very, very well. you know, the good news that we got from last night is that we're not expecting a category 3. the bad news is that 1 is plenty bad enough to cause an electrical outage, to cause flooding from heavy rain delays, that will come if the storm sits above us, but we have really taken a lot of time to prepare for this. the president called today, the federal, the state and the local authorities are leaning as forward as we possibly can. we feel confident that, given the storm as we know it to be right now, the levees that we have invested $14 billion into the american public helped us with, will hold. however every storm is different. this one particularly is very hard to predict and every one of them brings something that you would not expect. so all of them are very, very dangerous. so we're asking people again to be very vigilant. if you're going to leave, now is the time to leave. after tonight about 11:00 it's going to be a very inopportune time for you to move and then we

have to hunker down and ride it out and we've got to be prepared to respond very, very quickly to whatever consequences are that this storm brings us. >> mr. mayor, we're going to be thinking about you and your city over the next couple of hours and days and we hope to talk to you along the way. good luck to you and we hope everyone there is prepared. mitch landrieu, mayor of the city of new orleans. now to the event that brought us here, the republican convention. mitt romney's biggest opportunity yet to tell his story, reintroduce himself to the american public, after this long campaign season, and make his case, one final time. then, of course, along comes this storm. some of the best laid plans for this gathering had to go right out the window. our political director chief white house correspondent chuck todd with us in tampa. chuck, good evening. >> reporter: good evening, brian. you know, the biggest week in mitt romney's political career is obviously getting off to a late start and while confident they can make a shortened convention work, organizers fear

that if the storm causes more damage, it could cause further delays to their best laid political plans. with the bang of the gavel and a nearly empty hall, republicans began and then quickly ended business. >> republican national convention stands in recess. >> reporter: as mitt romney prepared for his big night with one eye on isaac. >> our thoughts are with the people that are in the storm's path and hope that they're spared any major destruction. >> it's good to be home. >> reporter: in wisconsin, paul ryan held a raucous send-off rally at his hometown high school in janesville. >> the next president for a few years, we are picking the pathway for america for a generation. >> reporter: still, isaac, not romney nor ryan, was the focus today. the louisiana delegation's empty chairs a symbolic reminder. their state's republican star and governor will be a tampa no show. >> certainly party conventions

are interesting but there is no time for politics here in louisiana along our coast. >> reporter: one staple of political conventions did remain today. wild rumors and political gossip, raising eyebrows this morning, a "new york post" report claiming that tomorrow's keynote speaker, new jersey governor chris christie, is quietly whispering to insiders romney's going to lose, something he denied in an interview for "morning joe." >> yeah, well it's just completely shoddy reporting, i mean, much of what was said in that story just wasn't true, so, and they never talked to me. >> reporter: flying in the face of the christie rumor a slew of new polls out today confirming a close race, romney up a point in a new national survey while down four in battleground florida. the tightness only underscores the importance of this convention for romney, as he debates how to reintroduce himself to the american public. >> all i can do is be who i am and remember that popeye line, i am what i am, and that's all that i am. >> reporter: even as romney invokes popeye, both he and his wife, ann, are determined to show they aren't the caricature

being painted in attack ads, even talking about their love of the bulk discount store, costco. >> she also got me one of the three-pack of shirts from costco the other day. they're very nice shirts. >> the kirkland shirts he's wearing them all the time. hey that shirt looks pretty good. i got it at costco. >> reporter: tonight's featured speakers were supposed to be south carolina governor nikki haley, former arkansas governor mick huckabee and former florida governor jeb bush. they instead will be appearing tuesday, wednesday and thursday nights respectively, brian. >> chuck todd on the convention floor behind us, thanks. at this point let's bring in the rest of our political team, david gregory is here with us in the studio, moderator of "meet the press" and andrea mitchell, veteran of many political conventions, is down on the floor of this one. andrea, starting with you, by how much have they been forced to ad lib their way through especially this format, their rundown? >> reporter: already they are squeezing a lot of these speeches and they have to deal with oversized egos and get them down to the size of the network

productions from 10:00 to 11:00 prime time. so they're squeezing. they've already lost a day and a half and they know they have to accomplish that, but both republicans and democrats, we should point out, have a challenge, a political challenge here with this approaching storm especially for the republicans. no one here can easily forgot the iconic picture of president bush flying on air force one looking out the window and looking down at new orleans during katrina. they're not going to forget that but democrats also have to be sensitive, brian. joe biden, the vice president canceled his plans to come to tampa and other cities in florida this week and sort of get in the face of the republicans. and the president leaving tomorrow for iowa, a three-day visit to battleground states, to college campuses, and he might have to cancel some of that as well. >> all right, andrea mitchell on the floor, david gregory, let's talk about image. we just saw some of it. >> yes. >> in chuck todd's setup piece,

this is a family that's been forced to talk about their rightfully gained enormous wealth, having been successful in business, the garage for their cars at their home in la jolla, california, now comes this, but it's part of a package they want to promote and discuss with the american people. >> you know, brian, i talked to republicans on the floor here and around this convention, giving some of himself, something that romney's got to do. that is the consensus. he's got to show more of his heart but there's also a recognition that he's not going to be able to beat back all of these negative images and at the same time he's not going to be able to be mr. inspirational, there's recognition that the analogy i heard today is the car mechanic. you may not love him, he may not light up the room but he can do to washington and fix things. that i think is going to be the master strategy. and i think that's what romney wants to leave people with, not just here but the people watching at home. >> david gregory, andrea mitchell and chuck todd, all of whom remain in place as this thing gets under way, and of course a reminder that our prime time coverage of this gop convention including ann romney's speech to this

gathering and chris christie's keynote address, that begins tomorrow night, 10:00 eastern, 7:00 pacific, on this nbc station. this has been a particularly violent day in afghanistan. u.s. military officials say two american soldiers were killed by an afghan soldier making this just the latest attack on u.s. forces by a so-called friendly. also insurgents beheaded 17 people, including two women at a dance and music party in an area of afghanistan controlled by the taliban, and in syria, rebels shot down an army helicopter this morning as it was bombarding a neighborhood of damascus, a rare rebel victory put out on the internet against government air power. when "nightly news" continues from tampa, there's a health story we need to bring you tonight, it's about women's health and breast cancer prevention. and later, hundreds of earthquakes in rapid succession in southern california, over the last few days. what they're calling a seismic

storm and tonight, what it all might mean.

as we've said there's a story in the news tonight about breast cancer, a new study that shows definitively weight is an important risk factor in determining if a woman will suffer a recurrence, and as many doctors have insisted, losing weight after diagnosis can lead to better outcomes all around. our report on all of it tonight from our chief medical editor, dr. nancy snyderman. >> reporter: breast cancer strikes almost 300,000 women a year. while cure rates have improved over the last 20 years, increasingly doctors are focusing on a certain group of women who don't fare as well as others. >> there's a clear connection between obesity at the time of a breast cancer diagnosis and an increased risk of occurrence of breast cancer. >> reporter: dr. joseph sparano is an oncologist who specializes in breast cancer at montefiore einstein center for cancer care

in new york and is a lead researcher of today's study which focuses on the most common type of breast cancer. >> we've known for a long time obesity is associated with an increased risk of breast cancer but what this study shows is that risk is there even if patients get optimal therapy. >> reporter: even after ruling out problems like heart disease, diabetes, kidney and liver disease, being clinically obese with a body mass index over 30 is an independent risk factor. the fat causes changes with insulin, estrogen and inflammation and serve as fuel for cancer cells. the study looked at almost 7,000 women with stage one to three breast cancer who required chemotherapy as part of their treatment. women who were obese when diagnosed had a 30% higher risk of recurrence and almost a 50% higher risk of death than women of normal weight. >> reducing weight could have an effect in terms of reducing the risk of recurrence. >> reporter: experts say even a weight loss as little as six

pounds can make a difference. in one study, leading to a 25% reduction in the risk of recurrence, which can be comparable to the treatment with chemotherapy. dr. nancy snyderman, nbc news, new york. up next here tonight, hundreds of earthquakes all bunched together, all in southern california. is there anything else we should know? is

if you've seen the news today or know anyone in southern california, or if you live there yourself, then you know there have been a cluster of over 400 mostly minor earthquakes, just over the last few days. it has a lot of people on edge, and the rest of us wondering why, and what's next. our report from there tonight from nbc's mike taibbi. >> oh, gosh. >> reporter: in the digital age you knew there'd be home video. >> our house is coming down. the house is coming down. >> reporter: this house in rawley, california, about 120 miles east of san diego, did not

come down, none did, but some 400 earthquakes over a several-hour period sunday did cause minor damage to scores of homes and buildings and even caused one hospital to evacuate its patients when power was lost. as predicted by a prototype early warning system at caltech's seismological lab, just about all of the shakers were relatively minor with a magnitude 3.0 range with a few just over 5.0. >> we were doing pretty well at estimating the magnitude of the earthquakes. >> reporter: say the words earthquake and california in the same sentence and the locals start worrying about how much they might lose. >> i was literally watching it and the pieces of the wall were falling. >> reporter: while the rest of they a ware of the computer models and movie versions of the history befalls to the obvious question. does this suggest any connection at all to the big one? >> and the answer is no. this earthquake is just happening too far south from the san andreas. we've seen many such swarms in rawley over the last century,

never followed by something on the san andreas. >> reporter: on an average california day, there are around 50 barely noticeable earthquakes statewide, but 400 in one day, in one spot -- >> i don't like this. >> reporter: -- were duly noticed. mike taibbi, nbc news, los angeles. as we mentioned at the top of the broadcast, a glimmer of hope for all those who someday hope to not have to put away all their electronic devices on planes. while we are all told they interfere with the aircraft, they're now going to reexamine that. the faa announced today it's put together a high level group that are going to take a few months, study it hard and then get back to us determining if the rules should be in place anymore. up next from us here tonight, a final update and one more thing about the last modest hero we ever had.

president obama today ordered flags at half staff for the burial of neil armstrong, who may have been the last truly modest hero our nation ever produced. much of the coverage of his life has dealt for good reason with his footstep and his footprint on the moon, but those who read more about him about find an astonishing american journey. by the time he was 22, he was

already a decorated naval aviator, a veteran of 78 combat missions over korea, he was later a test pilot, he flew in the experimental x-15 seven different times, topping out at 200,000 feet and flying along the likes of chuck yeager. as we said on the air upon news of his death saturday, there was never a neil armstrong action figure or chain of restaurants with his name. he did it for the team and he quietly walked away. he lived long enough to see the end of our manned space program, and that upset him greatly, but he also lived long enough to see those great pictures coming back from the mars rover, where they talked about neil armstrong today at mission control. he was all about courage, the quiet kind. he was a patriot of the highest order and thankfully right when america needed just the right man for that job, there he was. neil armstrong was 82 years old. he'll be buried in ohio on friday. that is our broadcast for this monday night from the gop

convention here in tampa. thank you for being here with us. an update on the storm on your late local news tonight and of course the weather channel, all evening long. i'm brian williams. we hope to see you right back here tomorrow evening. good night. -- captions by vitac -- www.vitac.com r right now at 6:00, no longer on death row, nearly 30 years after being convicted of a double murder in san jose. we'll tell you why this man is having his sentence changed. also, tropical storm isaac is swirling in the gulf of mexico, and it might impact our gas prices in the bay area right before labor day weekend. and coming home as heroes. petaluma little league team finally comes back to the bay area after the experience of a lifetime. nbc bay area news starts now. good evening, and thanks for joining us, i'm jessica aguirre. >> i'm raj mathai. tense