Extreme winter weather has caused travel delays for the national touring production of "Sister Act: the Musical," which was scheduled to open at the Kentucky Center for the Performing Arts tomorrow evening. Opening night has been pushed back to Wednesday, January 8, and all remaining performances will go on as scheduled. Tuesday night ticket holders may exchange their tickets for future performances. PNC Broadway in Louisville subscribers should call (502) 561-1003 for ticket exchange or account credit, and individual ticket buyers who purchased through BroadwayinLouisville.com should call that number as well.Tickets purchased directly from the Kentucky Center can be exchanged in person at the box office at 501 W. Main St. Call (502) 584-7777 for details. Tickets purchased from Ticketmaster.com will be automatically refunded, but tickets purchased from a Ticketmaster outlet will need to be exchanged at the original place of purchase.