Goodwood, Yarmouth and Wincanton are set to hold precautionary inspections at 6.30am, 7.30am and 8.00am respectively ahead of Thursday's meetings due to the prospect of more rain.
The going at Yarmouth is already described as heavy and amounts between eight and 33 millimetres are forecast which would put the fixture in serious doubt.
"We've had three millimetres of rain today and we are heavy," said clerk of the course Richard Aldous on Wednesday.
"The forecast ranges between eight and 33 millimetres. I think it can take between five and seven, I'm not sure, but if we get anywhere around 10 or more I'd be very worried."
Although Goodwood clerk of the course Seamus Buckley reports the track to be "perfectly raceable", he is worried too much rain would compromise the fixture.
"There's a possibility of 10 to 12 millimetres of rain overnight," he said.
"We are perfectly raceable, but in view of that we thought it would be right and proper to have a precautionary inspection at 6.30. We wouldn't want 12mm. We could take five. Anything more than that I think would cause us concern."
