Practice for the Classic TT and Manx Grand Prix was cancelled for the second night running on Tuesday evening due to poor visibility.
Clerk of the Course Gary Thompson had signalled his intention to press ahead with practice as planned after completing a course inspection lap in the afternoon.
Roads closed around the course at 6pm but soon afterwards it was announced that the session had been called off as mist began to roll in.
Thompson has confirmed a daytime practice session will be held on Thursday to make up for lost time.
“Despite our best efforts, unfortunately tonight’s practice/qualifying is cancelled due to poor visibility on the Mountain,” he said.
“Next session is tomorrow evening and we will also be looking to practice on Thursday afternoon as well as Thursday evening.”
Wednesday's qualifying programme will now be as follows:
18.00 - Roads close around the course
18.20 - 19.05 MGP Senior/ MGP Junior/ CTT Lightweight/ CTT Superbike (no newcomers)
19.10 - 19.45 CTT Junior/ CTT Senior/ MGP Lightweight & Ultra Lightweight
19.48 - 20.00 MGP newcomers accompanied by experienced riders
Thursday's qualifying programme will see roads close around the course at 12.30pm with the first qualifying session running from 1pm to 3.55pm.
The roads will then open again at 4.30pm around the course and close again at 6pm for the scheduled evening qualifying session.
So far, only Saturday’s session has take place, denying competitors track time ahead of Saturday’s opening Classic TT Senior and Lightweight races.