The meeting at Towcester on Sunday is subject to a precautionary 8.30am inspection on Friday.
While the going is described as good to soft, soft in places, there are areas of standing water.
Further heavy rain is forecast on Thursday night and Friday.
Clerk of the course Robert Bellamy said: "We've been dry today but we had 19 millimetres of rain yesterday and have standing water in places.
"The forecast for tonight and tomorrow is pretty horrendous and it doesn't look good at this stage, but we'll reassess things in the morning and see where we are."