If you are going to pull out of a tournament, especially between rounds...let the TD know as soon as you decide. Things happen...some people don't like to play in adverse weather, some people injure themselves and may not know it right away or may think they can play through it. Let the TD know. Why? In sanctioned rounds, cards are required to be three or more players. If you are assigned to a card and would be a fourth....but don't show up...now the card is at their minimum. What happens if another cardmate didn't show up? Or if the card was a threesome to begin with. Now the card (if they know the rule) and the TD have to scramble to get the two-some onto another card. I was in a tournament where I had the trifecta: 1) I was in last place after round one, no chance to improve (I was that far behind), 2) it started raining before the second round (same day, second round was after lunch), and 3) I had hurt my ankle. I considered not showing up, but did anyways. For me...I paid, I was going to play even though I dislike playing in rain and had to throw standstill because of my ankle injury. It was a shotgun start, so when I got to my tee, I found another player had decided to not show. I got to talking with the other two on my card and found out it was their first tournament and they didn't know the rule about 3 or more on the card. They were two ladies who actually ended up in the running for their division....if I hadn't shown up, they would have played as a twosome, not knowing that wasn't allowed. It probably would have ended up with them disqualified. And being a shotgun start, the TD wouldn't have known they were playing as a twosome.
So while it is your choice as to whether you play or not, regardless of the reason, always let the TD know as soon as you can....that way the TD can make any adjustments needed prior to the start of a round.