Inspections will take place at Wincanton and Fakenham on Thursday as National Hunt racing continues to come under the grip of the weather.
Wincanton will hold a precautionary check at 8am, while officials at Fakenham will assess conditions at 7am.
Friday’s meeting at Catterick is already in doubt with an 8am inspection called for Thursday.
The course tweeted: “Ahead of the meeting on Friday we are currently good, frozen in places. With the cold weather to continue, there will be an inspection at 8am tomorrow.”
And the opening day of the weekend Cheltenham Trials meeting at Musselburgh is also under threat, with an inspection being called for midday on Thursday to assess prospects for Saturday.
The British Horseracing Authority has added an extra fixture for Saturday, on the all-weather at Chelmsford.
There was no jumps action on Wednesday, as the cards scheduled for Plumpton and Leicester were both called off.
Plumpton’s clerk of the course Mark Cornford inspected the track at 7.30am and while the frost covers largely protected the ground, the meeting was scuppered by a covering of snow.
Cornford said: “It’s really annoying. We put the frost covers down and when I lifted one, it seemed to have protected the ground underneath.
“However, there is a layer of snow on the track which is more like frozen ice and it’s stuck to the covers, which means we can’t take them up.
“There’s nearly 200 covers out on the track and it’s just an impossible task to raise them all in time. We’re not forecast a positive temperature until 10am, or perhaps later than that.”
Leicester clerk of the course Jimmy Stevenson had planned to check conditions at 8am but was able to make an earlier call.
He said: “We didn’t get the snow, but it did rain and that has just set on the ground and frozen solid.
“It went down to minus 5C overnight and it’s not going to get up to 1C before midday.”
There was good news from Lingfield though, with the all-weather card given the go-ahead following a precautionary 8am check.