Weather conditions may cause issues for qualifiers
Manx Grand Prix organisers will make a decision about this evening's practice session at around 3pm.
Weather conditions around the Mountain Course mean tonight's scheduled qualifying may not be able to take place.
Roads are currently due to close at 6pm, with the first bikes departing the Grandstand at 6.20pm.
If the session can go ahead, roads are expected to reopen by 9pm.