requires the coexistence of "space and time and myth" and/or of "conflicting realities";
temporarily relocates people from different times and places to the Worlds' End Inn.
This kind of storm is impossible in Poul Anderson's Time Patrol universe because, in that universe:
myths are not real;
conflicting realities do not coexist but succeed each other;
spatiotemporal displacement occurs only through the mechanism of a vehicle like a time shuttle or timecycle;
there is no inn at the end of the world.
This universe does include unstable space-time zones within which a time traveler might encounter or inadvertently cause a causality violation. Such zones are this universe's closest approach to a reality storm.
By contrast, in the Old Phoenix multiverse:
that which is a myth in one universe is sometimes a reality in another universe;
alternative versions of reality do coexist;
in some universes, magical events can include mysterious disappearances and reappearances, e.g., Holger Danske;
some conflicts are transcosmic;
there is an inn between the universes.
Thus, most of the conditions for a reality storm are in place.