CAPE CANAVERAL, Fla. – On the eve of the next-to-last space shuttle launch, thousands of people streamed to the region for a chance to watch today’s fiery spectacle.

Adding to the fever-pitch excitement: The first-ever visit by an entire presidential family.

Also watching Endeavour’s final liftoff will be the shuttle commander’s wounded wife, Rep. Gabrielle Giffords.

The crowd estimate surged Friday to 700,000 or more, as people scrambled to witness a launch before NASA closes out the 30-year era of space shuttle flight this summer.

“This is something that is on everybody’s bucket list,” said Rob Varley, the area’s top tourism official. “For many people, it’s like ‘Uh-oh. We only have two more chances to see one.’ “

Discovery’s final launch in February also drew large crowds — but that was a mere 400,000.

“People standing on their cars, standing at all these different locations, things we probably haven’t seen since the late ’60s when we were going to the moon,” NASA flight director Jeff Spaulding said. “That in itself is kind of awe-inspiring.”

As the countdown entered the final hours, forecasters revised their take on this afternoon’s weather.

There was a 30 percent chance that low clouds or stiff crosswind could force a delay, a slightly deteriorating outlook.

The storm that pummeled the South was expected to reach central Florida late Thursday — although not nearly as strongly — and be well past by the time NASA starts fueling Endeavour at dawn today.

Giffords’ whereabouts, meanwhile, were being kept secret. She is married to Endeavour’s commander, Mark Kelly, who will lead a six-man crew to the International Space Station. They’re delivering spare parts and a $2 billion particle physics experiment aboard the shuttle.

A staff member for Giffords said in a Twitter update late Thursday that the congresswoman was enjoying Florida and “all the space action.”

She arrived in Cape Canaveral on Wednesday, leaving behind the Houston hospital where she has been undergoing rehab for three months.

Giffords survived an assassination attempt Jan. 8 at a political event in her Tucson, Ariz., hometown. She was shot in the head; six people died and 12 others were wounded. A 22-year-old suspect is in custody.