Exeter will hold a second inspection at 10am to determine whether today's meeting can go ahead.
The track was found to be raceable at an 8am inspection after soaking up 12 millimetres in the early hours very well.
However, as much as 20mm of rain is forecast before 1pm which would put the fixture in jeopardy.
"The course has taken the rain really well and we could race on it now. However, more rain is forecast, so we will just have to see what transpires," said general manager Tim Darby.
"It would be such a shame to lose the card as it is such a good meeting."
The card is sue to feature a clash between exciting young recruits Puffin Billy and Melodic Rendezvous in the Listed Bathwick Tyres Plymouth Novices' Hurdle.
Monday's meeting at Catterick is subject to 8am inspection on raceday morning due to the possibility of snow.