Sunday's meeting at Hereford is in serious doubt due to a frozen track.
An inspection has been called for 8.30am on Friday and to stand a chance of racing, there needs to be a significant improvement in the forecast.
Clerk of the course Keith Ottesen said on Thursday: "They declare for Sunday tomorrow morning so that's why we'll look at 8.30am.
"The forecast is for another below zero night and it's as bad this morning as it has been all week. There could be some snow tonight and there is a severe frost forecast also.
"We need a drastic shift in the forecast to have any realistic hope."
