Today's meeting at Ayr is subject to an inspection at 7 a.m. because of further rain and a wet forecast.
"We have had bits of rain today and one hefty shower - about one fifth of an inch in all - and the course is barely raceable," said clerk of the course Mark Kershaw yesterday.
"Further substantial rain is forecast tonight, putting the meeting back in doubt," he added.
The stewards have already inspected the course twice, on Thursday afternoon and again yesterday morning. The going is now heavy on all parts of the course.
However, no problems are reported from any of the other four fixtures.
Newbury stages the day's main meeting, featuring the £15,000-added Mandarin Handicap Chase - one of three races live on BBC1.