After an early morning inspection, Saturday's meeting at Navan has been cancelled, with the track unfit for racing following heavy overnight frost.
The County Meath venue was due to host a seven-race card, but the 8am check left officials with no choice but to cancel.
Haydock's Peter Marsh meeting will go ahead after the course passed an early-morning inspection.
The card was subject to a scheduled 8am check because of the threat of frost, having already survived the ravages of the midweek Storm Christoph.
However, the inspection was brought forward to 7am, and a Tweet from Haydock’s official account confirmed shortly after 7.15am that the course was fit for racing.
Taunton’s eight-race card was given the go-ahead before a scheduled 8am inspection there too, as overnight conditions relented sufficiently.
The ground at Taunton is soft, heavy in places – as it is at Ascot, where the Grade One Matchbook Betting Exchange Clarence House is the highlight of a seven-race card.