I cannot comment on the weather, as my friend's departure was delayed by technical matters.
However ... whilst waiting for the flight to go (4 hours late and counting) I noticed another problem with the new T3 car park. I commented on the poor lifts when I first used it in July. Today, the two llifts at the South end were flashing 'ALARM' on their display screen (the one inside the car) alternately with "LIFT UNDER FIRE CONTROL" or something similar. In fact the lifts were operating normally and continued with this erroneous message across the three hours or so that I was in the terminal.
Another triumph of product selection by BAA.