The big freeze looks set to disrupt one of the key stages of the jumps season with Cheltenham preparations for some of the sport's biggest stars facing turmoil less than eight weeks before the start of the Festival.
An Atlantic weather system bringing snow to vast parts of Britain is forecast for Friday with the weekend's prize meetings at Ascot and Haydock under threat of abandonment.
Ascot is scheduled to host the Grade 1 Victor Chandler Chase, featuring Sportingbet Queen Mother Champion Chase favourite Sprinter Sacre, on Saturday but a Met Office spokeswoman said on Wednesday that the course could expect in the region of 2-5cm of snow on Friday coupled with freezing overnight temperatures.
Clerk of the course Chris Stickels said: "We've got the covers down and are raceable at the moment. There's a high risk of snow on Friday, which would cause more problems, and the meeting has to be considered to be under threat in light of the forecast."
Cheltenham contenders Peddlers Cross, Bold Sir Brian and Katenko are among the runner pencilled in for Haydock's fixture on Saturday although the prospects of racing going ahead appear slim.
There is an 8.30am inspection at the course on Thursday and contingency plans have already been discussed by the BHA over the possibility of restaging races should the meeting fall to the weather.
Clerk of the course Kirkland Tellwright said: "The forecast is for a hard frost overnight and we may well know our fate tomorrow. If the frost is as hard as forecast we're likely to abandon, if not and there is any hope we'll call a further inspection, which is the best outcome we can hope for."
Optimism for Saturday is higher at Taunton where Hunt Ball is due to run in the 2m3f handicap chase on the track's most valuable raceday in its 85-year history.
Head groundsman Keith Councill said: "There's been no talk of an inspection at this stage and it is the snow that is the biggest threat to us."
Thursday's cards at Ludlow and Market Rasen are already abandoned but Wincanton hopes to keep the show on the road by passing an 8.30am inspection.
"We're fine under the fleece at the moment, but with the temperature of -4C overnight we've decided to inspect in the morning," said clerk of the course Barry Johnson.
Friday's fixtures at Musselburgh and Chepstow also hinge on inspections at 8.30am and midday respectively, while Towcester will have called a 9am check today for Sunday's meeting.