TT I am afraid you may have the wrong open day. That one was CAVOK all day long, a clear blue sky in which the Red Arrows did their full show, and no, my Noddy Train didn't encounter any pedestrians.
The only strange met. phenomenon that weekend was that overnight, after the open day, the south west wind got up and blew all the litter off the airfield until it impaled Missile City's chain-link fence. Clearing up the litter then became a linear rather than area job and took, IIRC, about 45 minutes just to walk along and pick the rubbish out of the fence and bag it.
Happy days.