Auto body repair & detailing: 04 Yukon Door gap, rubber mallet, door latch

Question
I have a 2004 Yukon and as I drive on the interstate I recently started noticing wind noise around the upper portion of the driver's door.  Upon inspection the upper front corner of the door (behind the "A" pillar) as it meets the roof line has an increased gap (outward not up). This gap is almost double the norm and runs for about 12 inches.  The door has never had damage and I can't find anything else out of alignment.  What could cause this and is there an easy fix?  Thanks and Happy New Year!!

Answer
Take a large rubber mallet, and place it in the door jamb about where the striker meets the door latch. This will prop the door open about 4 inches. Roll down the window all the way down. Now, you need to give several strong pushes to the upper rear door frame- don't put your fingers into the jamb area, in case the mallet slips out (Ouch!) You may need a fairly tall person to accomplish this. I know, it sounds a little primitive, but your door has welded hinges- there areno traditional adjustments. Bill