Fontwell's jumps fixture on Sunday must pass a 3pm course inspection on Thursday afternoon.
Despite a dry night, the track is still heavy, waterlogged in places.
A lot more rain has been forecast over the next few days.
Clerk of the course Ed Arkell said: "It's not looking promising. "We had a dry 24 hours but there's been no improvement - if anything, it's got worse - and it's just started raining again now.
"More rain is forecast on Saturday and large numbers on Sunday.
"Unless the forecast is radically wrong we face an uphill task.
"We've had 14.4 inches of rain since December 14."