Heavy rains forced the cancellation of Friday's Joe Aitcheson Hurdle (NSA-I) at Pimlico Race Course. The rain began Thursday night and intensified Friday morning. The forecast was for the precipitation to continue all day Friday.Officials from Pimlico and the National Steeplechase Association hope to reschedule the race, but no specific date has been set yet.The three other grass races on Friday were taken off the turf, forcing a large number of scratches. Included in those three races is The Very One Stakes, which has four horses scratched from the 12-horse field.In the grade II Black Eyed Susan, there is only one scratch, Austin's Mom. There are no scratched in the grade I Pimlico Special.