Bangor on alert
Bangor must survive an 8.30am inspection on Thursday if Friday's meeting is to go ahead.
The ground is heavy after three millimetres of overnight rain, but further heavy showers have been forecast.
Up to 17mm of rain could fall within the next 48 hours.
Clerk of the course Andrew Morris said: "We got away quite lightly last night as we only had 3mm of rain. We thought we'd get quite a bit more than that.
"We'd just be fit to race this morning, but it is borderline and there is further rain forecast for later today.
"Having an inspection in the morning just gives us a chance to see where we stand, but we couldn't take any amount of rain, really."