The Merseyside track has been frozen since last Wednesday, with overnight temperatures plummeting to minus 5C and daytime highs inadequate to bring forth a thaw.
Officials are "struggling" to get the ground fit for their scheduled card, which features the Betfred Tommy Whittle Handicap Chase, and an inspection is planned at 8am on Thursday.
On Tuesday morning, Tellwright said: "Frankly, we are struggling. There is a modest thaw starting on Friday, but on all the evidence, it won't be sufficient or in time.
"We will inspect on Thursday and are likely to call it off then. If there was any prospect of being on, we will, of course, call a further inspection."
Meanwhile, Ascot has moved to scotch speculation that should Friday and Saturday's scheduled meetings be lost to the inclement weather, they could switch the cards to Sunday or Monday.
The two-day card includes a pair of Grade Two contests, with the Porsche Kennel Gate Novices' Hurdle and the Howden Noel Novices' Chase on Friday, and the Grade One Howden Long Walk Hurdle on Saturday.
However, the prospects for both cards to get the green light are receding, with frost in the ground and no sign of a thaw before the weekend.
Clerk of the course, Chris Stickels, said: "Moving the meetings to Sunday or Monday is not on our radar.
"People don't know how the intricacies work. It is really complicated in order to get that kind of thing done. Also, we now have snow forecast for Sunday morning.
"What happens in this situation is the Grade One races tends to get moved, so the BHA will reschedule that if they feel it is required.
"But as we speak, the forecast doesn't look very promising for racing on Friday. The weather needs to be better than is currently forecast."
Prospects of jump racing in Britain this week could hinge on the forecast for Thursday's meeting at Ffos Las.
The going at Ffos Las is currently described as good, with a light overnight frost, although temperatures are forecast to drop to minus 2C on Tuesday night and minus 5C on Wednesday night.
Precautions have been taken at the Welsh track, with frost sheets laid, covering whole of both straights.
The meeting at Naas on Thursday is subject to a precautionary inspection at midday on Wednesday.
Irish Horseracing Regulatory Board clerk of the course, Brendan Sheridan, said: "The ground at Naas remains yielding to soft however parts of the track are currently unraceable. Due to the weather forecast from Met Eireann we will have a precautionary inspection at 12pm on Wednesday."