Officials at Cheltenham believe the weather over the next 48 hours will be crucial as to whether their Festival Trials meeting will go ahead on Saturday.
Although the course is raceable under the protective covers, it remains very cold and more snow is forecast before a hoped-for improvement in the second half of the week.
Clerk of the course Simon Claisse describes the meeting as "being in the balance" and expects a better idea of prospects by Wednesday morning.
"The course remains raceable under the covers. The temperatures are below freezing and there is a just a touch of very light snow in the air," he said.
"There is the chance we will get further light snow tomorrow with temperatures beginning to get better by Thursday/Friday and rain on Saturday.
"I think it is still very much in the balance at this stage.
"We will remove the covers when most of the snow has thawed and that is where we need the help of not too much more snow tomorrow and milder air by the end of the week.
"I think the next crucial stage in our thinking will be after we have had the snow that's forecast for tomorrow and tomorrow night.
"I think we will have a pretty good idea as to the way it's heading on Wednesday morning."
Prospects of any turf racing in Britain before the weekend look slim at present as snow continues to fall.
Ayr are hoping to race on Wednesday after the British Horseracing Authority awarded them an extra meeting, but snow now features in their forecast.
Clerk of the course Emma Marley said: "We are perfectly raceable at present. We were 1C overnight and 2C yesterday.
"However, the forecast is for light snow tonight and into tomorrow morning, one to two centimetres.
"We'll have a better idea of our chances in the morning, but the forecast is slightly problematic.
"All we can do is wait and see as it is coming in from the east coast and it is quite heavy over there."
Catterick's meeting, also on Wednesday, has already been abandoned after an inspection.
Clerk of the course Fiona Needham said: "It has not actually been that cold over the weekend, but it's snowing again as we speak and it's not going to improve.
"Our next meeting is February 1 so let's hope things have improved by then!"
Turf meetings at Leicester and Wetherby on Tuesday had already been lost to the weather but there is a chance of racing at Exeter on Wednesday, although they need the forecast to go their way.
"We've got a glimmer of hope," said clerk of the course Barry Johnson who will inspect at 8am on Tuesday.
"We're not too sure what's going to fall overnight, it could easily be snow which would give us no chance, but it may be rain or sleet which would help shift the snow.
"It depends on tomorrow morning and we'll know by 8am."
Warwick's meeting on Thursday has already been abandoned after an impromptu 11am inspection was called by clerk of the course Sulekha Varma.