This NASA picture perfectly shows the reason why shuttle Endeavor is still on the launch pad... Florida is, of course, notorious for its weather. After all, it is currently Hurricane season, but fortunately NASA has not had to deal with one of those during this launch countdown. No, these things just happen, and NASA is very cautious with the shuttles as they should be. Good luck to the STS-127 crew today, who hope to take off at 4:51 p.m. Mountain time.
SpaceRef reported Saturday that the launch tower was repeatedly struck by lightning during an intense thunderstorm before the launch time; just take a look at the picture and consider whether you, too, would put the launch on hold to investigate all systems and look for possible damage. Of course, the launch tower lightning capture system is perfectly designed for this sort of thing and it appears all is well for Endeavor and I'm looking forward to the launch.