(CNN) -- A powerful storm including a lightning strike in the launch pad area caused minor damage to the space shuttle Endeavour, a NASA official said Thursday.

Continuing bad weather has prevented further inspection of the shuttle scheduled to launch on its final mission on April 19, said Allard Beutel, a spokesman at NASA's Kennedy Space Center.

The storm Wednesday included a wind gust of 90 miles per hour at launch pad 39A, as well as a lightning strike "inside the pad perimeter," Beutel said.

"We didn't take a direct strike on the pad," Beutel said. "Anytime you get that much electricity inside the perimeter you have to check things."

NASA officials so far know of minor damage to insulation foam at the top of the shuttle's external fuel tank, according to Beutel, who said a full assessment of damage won't be possible until further inspections take place.

NASA says the storm that included high winds, lightning and hail blew in at about 5:20 p.m. Wednesday.

"No one was injured and initially no obvious damage was observed. The storm moved through the area quickly," said a NASA news release Wednesday.

Endeavour is scheduled to blast off to the International Space Station on April 19. The space shuttle's six astronauts are at the Kennedy Space Center for their launch dress rehearsal.