Romney's convention planners said they were in frequent contact with weather forecasters, but they declined to discuss what contingency plans, if any, they had to accelerate plans for him to deliver a formal acceptance speech Thursday night.
"This is obviously the biggest speech of my life," Mrs. Romney said as she visited the custom-made podium to prepare for her remarks.
Ratification of a party platform was prelude to Romney's nomination, a document more conservative on abortion than the candidate.
On economic matters, it backs extension of the tax cuts enacted in 2001 and 2003 and due to expire at year's end, without exception. It also calls for an additional 20 percent reduction in income tax brackets that Romney favors.
In a time of 8.3 percent unemployment and the slowest economic recovery in the post-World War II era, that went to the crux of the campaign for the White House.
By contrast, Obama wants to allow existing tax cuts to expire on upper income taxpayers, and has criticized Romney's overall economic plans as a boon to millionaires that would raise taxes on the middle class.
The GOP platform also pledges that a Republican-controlled Congress will repeal, and Romney will sign, legislation to repeal the health care legislation Obama won from a Democratic-controlled Congress. So, too, for the measure passed to regulate Wall Street in the wake of the 2008 economic collapse.
On abortion, the platform says, "The unborn child has a fundamental individual right to life which cannot be infringed."
Romney opposes abortions, except in cases of rape, incest, or when "the health and life of the mother" are at stake, he said in a convention week interview.
Obama, who accepts renomination at the Democratic National Convention in Charlotte, N.C., next week, campaigned in Iowa Tuesday as he set out on a tour of college campuses in battleground states in hopes of boosting voter registration among college students.
Before departing the White House, he made a point of appearing before reporters to announce the government's latest steps to help those in the way of Isaac. He signed a declaration of emergency for Mississippi and ordered federal aid to supplement state and local storm response efforts in the state.
His surrogates did their best to counter Romney and the Republicans.
Los Angeles Mayor Antonio Villaraigosa, dismissing GOP attempts to woo Hispanic voters, said, "You can't just trot out a brown face or a Spanish surname and expect people are going to vote for your party or your candidate." He added, "This is a party with a platform that calls for the self-deportation of 11 million people."
Hispanics strongly favor Obama, according to public polls, and Romney and his party have been seeking to win a bigger share of their votes by emphasizing proposals to fix the economy rather than ease their positions on immigration.
Female voters, too, prefer the president over his challenger, and Democrats have done their best to emphasize GOP opposition to abortion and even suggest the party might try and curtail access to contraceptives if it wins power.
Whatever the impact of those issues, the polls show the economy is overwhelmingly the dominant issue in the race, and on that, the voters narrowly say they trust Romney more.
In an AP-GfK poll taken Aug. 16-20, some 48 percent of registered voters said they trust Romney more on economic issues, to 44 percent for Obama.
However, a Washington Post-ABC News in the days immediately before the convention found that 61 percent of registered voters said Obama was more likable, and 27 percent said Romney.
The convention took place in an atmosphere of security that was both stringent and selective. Thousands of police from all over the country, joined by National Guard troops, Secret Service and others, stood in small groups at checkpoints, demanding those entering a secure area display proper credentials numerous times.