Newcastle have been forced to abandon their Fighting Fifth fixture on Saturday after the course failed a precautionary inspection at 2.30 pm on Friday.
Officials were forced to call an inspection due to snow and near-freezing daytime temperatures, but with below-freezing temperatures expected overnight an early decision was made to abandon.
The fixture was set to host Constitution Hill's reappearance in the Grade 1 feature Fighting Fifth, while stablemate Shishkin was due to carry a huge weight in the Rehearsal Handicap Chase after refusing to race at the start of his intended return to action at Ascot last weekend.
Clerk of the course Eloise Quayle said: "We're absolutely gutted. We've had five centimetres of snow in total, and we tried to have a practice run of taking the frost sheets off with the snow on, which first of all proved incredibly difficult, then secondly as we were taking them up the ground was freezing over behind us.
"The ground wasn't frozen as we were taking them off, but within half an hour it was white over. Given we were having our warmest temperatures at the time we were taking them off, coupled with the difficulties taking them off in the first place, I think we were pretty hopeless, sadly.
"We've tried everything we can, but unfortunately sometimes you just can't beat the weather."
Newbury raced without any real issues on Friday, but a precautionary inspection has been called for 7.30 am ahead of Saturday's Coral Gold Cup card.
Elsewhere around the UK on Saturday, Doncaster are also subject to passing a 7.30 am inspection.
Fairyhouse will also inspect at the same time ahead of their highly-anticipated two-day fixture this weekend.
Brendan Sheridan, Irish Horseracing Regulatory Board clerk of the course at Fairyhouse, said: "We had a slight grass frost at Fairyhouse this morning following a cold night, but the track is currently fit for racing.
"Having spoken with Met Eireann this morning, the forecast for tonight is for temperatures to get down to minus 3C and not much higher than 2C tomorrow.
"In light of that forecast, we will have an inspection at 7.30am on Saturday morning to assess the situation for day one of our Winter Festival."
