Hey @AndrewRigby! I'm so excited for your adventure! What's bringing you out to the Smokys?! Are you backpacking at all, or will you be able to experience lots of different areas of the park with day hikes?
I would definitely say prepare for rain. The fall/winter in the southeast are incredibly wet, and the Smokys specifically get their name from how humid the environment is. That being said, it makes for some great photo ops if you wait out the sunshine. It will be a cold rain, too, so you'll want an insulating jacket, base layers, and a raincoat. Maybe even some gloves. Average lows are near freezing for this area in late November, but it feels colder in the south because of the humidity. If you're backpacking, don't forget to sleep with your water filter at night so it doesn't freeze. If you're day hiking, bring it in from the car each night.
In late November, there's a possibility of snow. If you get to the Smokys and you realize you don't have enough cold weather gear, our Pigeon Forge store just opened last weekend!
Since you only reached out regarding clothing, that leads me to believe you have your trip nailed down, but if you want any help trip planning, feel free to reach back out. I love helping people plan adventures! 😄
Taken last June while waiting out a sunset rainstorm. 🙂