Anyone who's been to AirVenture in weather other than the crystalline blue skies that this show often enjoys knows—or should know—one overarching fact about Oshkosh air operations: IFR and AirVenture don't mix very well. While some people insist on flying IFR into Oshkosh just because they file IFR to go everywhere, it's really not a good idea. ATC imposes a slot system for arrivals and although it handles reasonable volume, when the weather really tanks, as it did Sunday morning, arrivals will slow to a crawl.
This is a companion discussion topic for the original entry at https://www.avweb.com/air-shows-events/airventure-2018-ads-bs-dark-side