Guest host David Sedaris presents stories that reimagine holiday rituals. In Tobias Wolff’s “Powder,” a pre-Christmas snowstorm provides an adventure for a father and son. SELECTED SHORTS’ late host and founder Isaiah Sheffer is the reader. A long-established couple turn out to be able to surprise one another in Allegra Goodman’s gentle borrowing from an O. Henry classic. Dana Ivey and Michael Cerveris read her “Gifts of the Jewish Magi.” And David Sedaris says English writer Jeanette Winterson captures the city to a “T” in “Christmas in New York,” a modern fairy tale with just a hint of magic, performed by Richard Masur.