Supersport moved following mist and rain
Organisers will look to squeeze four races into tomorrow's TT schedule.
The second Supersport race had been due to take place this afternoon, but damp and misty conditions have continued to affect some parts of the Mountain Course.
The Lightweight is still due to go ahead this evening at 6.30pm, although it has been shortened to three laps.
Tomorrow's race schedule is as follows:
12.15pm - Superstock
2.15pm - Sidecar Race Two
4pm - TT Zero
6.30pm - Supersport Race Two
The Senior TT is currently scheduled to start at 10.30am on Friday, having been brought forward because of bad weather forecast for later in the day.