You can also add a second temporary water bowl over on the warm side to help bump up that humidity for the shed or add in a humid hide. To make a fast, cheap humid hide just take an appropriate sized margarine tub...snap on the lid...flip it over and cut out a small entrance hole....add in either spaghnum moss or just a pad of paper towels...the moss or towels should be damp not dripping wet and need to be checked daily....set it on the warm side of the enclosure...some snakes like humid hides...some don't but it's worth a try to see if yours is one that does.

Best of luck with the upcoming shed.