Convention organizers acknowledged they were monitoring Isaac, which made landfall one day before the seventh anniversary of Hurricane Katrina's devastating march through Louisiana and Mississippi.
They are concerned about the perception of a celebratory convention with colorful balloons and soaring rhetoric juxtaposed with a storm slamming the Gulf Coast at the same time, potentially evoking memories of Katrina's wrath and ensuing criticism of the response of the Republican administration of George W. Bush.
However, Romney and Republicans are reluctant to lose any more of their best opportunity to define the candidate for the American people with less than three months until the election.
"He is a very shy guy. He is a humble guy. He doesn't like to talk about himself. That's who he is," Boehner said of Romney in an interview Tuesday with CNN. "But I've known Mitt Romney for a long time. Decent, honest, hardworking guy. And I think Thursday he'll have a chance to reintroduce himself to the American people."
The acceptance speech will give Romney a major chance to speak for himself, rather than be defined by either his Republican primary rivals or by Obama, Boehner said.
"He's been locked in this Republican primary and then locked into this battle with the president," the Ohio Republican added. "And as a result, people have all different kind of views of him. So I think Thursday night is clearly an important speech for him and I think he'll have a chance to reintroduce himself to the American people, most of whom are just paying attention now."
For Romney, 65, the nomination will put him closer to the goal he first sought in 2007 by running for president after serving as a Republican governor for four years in traditionally Democratic Massachusetts.
The multimillionaire businessman lost to veteran Sen. John McCain in the Republican primary campaign in 2008, then spent the next two years preparing for another try. He emerged victorious from the primaries during which rivals challenged his conservative credentials, and continues to walk a political tightrope that attempts to galvanize right-wing support while also trying to appeal to moderates and independent voters.
The Romney campaign and Republicans have a big fund-raising advantage over Obama and Democrats, due in part to unlimited private donations to conservative super-PACs.
The latest CNN/ORC International poll indicates a dead heat between Romney and Obama, with new numbers released Sunday showing that 53% of likely voters believe Obama is more in touch with their needs, compared with 39% for Romney.
Obama leads by an equal margin when it comes to being in touch with the middle class, and six in 10 say Obama is in touch with the problems facing women today, with just over three in 10 feeling the same way about Romney.
Romney leads 48% to 44% over Obama on managing the government effectively and has a six-point advantage on having a clear plan for fixing the nation's problems. Both figures are within the survey's margin of error.
"The challenge facing Romney at the GOP convention is to build on those managerial strengths while at the same trying to convince average Americans that he is in touch with their problems. Obama's personal characteristics, for the moment, outshine Romney's," CNN Polling Director Keating Holland said.
On specific issues, the poll results show a similar dynamic: Obama is generally ahead on foreign policy and social issues, while Romney is generally preferred on economic issues.
Another new poll released Monday showed Romney and Obama neck-and-neck in Florida, a battleground state, and North Carolina, where the Democratic convention will take place next week.
Republicans say the Republican convention must focus on Romney's character and show how he can lead the nation to economic prosperity, which is the top issue with voters.
The Obama campaign, anticipating a Romney branding effort by Republicans, released a movie trailer-style video Sunday that previewed a "do-over" moment for Romney.
In a statement accompanying the video, the Obama campaign said it is "presenting Americans with an epic cinematic preview of Mitt Romney's 'convention reinvention' -- the Do-Over moment that voters have grown to expect -- because they've seen this movie before."
The GOP platform contains traditional conservative planks, including support for the "human life amendment" with no exceptions to an abortion ban. That runs counter to overall public opinion in America, especially among women, a demographic that polls show favoring Obama far more than Romney at this point.
Romney and Ryan, the conservative House Budget Committee chairman, have been asked repeatedly about differences between their personal views on whether there should be limited abortion exceptions.
Romney's Mormon faith calls for the narrow exceptions, while Ryan, a devout Catholic, supports a blanket ban. The campaign has made clear the ticket supports Romney's stance, which contrasts with the party platform.
The only speaker Tuesday night to touch on the abortion issue was conservative Rick Santorum, who attacked Romney's conservative credentials in the Republican presidential primary campaign. In his speech, the former senator from Pennsylvania backed Romney to end what he called destructive policies of Obama that undermine American values.
"I thank God that America still has one party that reaches out their hands in love to lift up all of God's children - born and unborn - and we say, and we say that each of us has dignity and all of us have the right to live the American Dream," Santorum said to cheers.