Chepstow’s meeting on Wednesday is subject to a precautionary inspection at 8am on Tuesday due to the threat of waterlogging.
The ground is already heavy at the Monmouthshire venue and significant further rain is forecast.
Having been hit by 55 millimetres of rain last week, anything between 15 and 40 millimetres could fall overnight into Tuesday morning.
Tuesday afternoon and Wednesday are due to be mostly dry with the wind picking up throughout the day.
Clerk of the course Libby O’Flaherty tweeted: “Precautionary inspection @Chepstow_Racing tomorrow morning 8am after increased rainfall forecasted overnight and tomorrow morning.”