Caulfield track manager Jason Kerr is hoping the predicted rain ahead of Saturday's Cup meeting is at the lower end of the scale.
On Friday morning the track was rated a Good 4, bordering on a Good 3, after 3.1 mils of rain fell on Thursday night.
However, the Bureau of Meteorology is predicting anywhere between 10 and 25 mils on Saturday with a 100% chance of it occurring.
The lesser amount would see the Caulfield track rated in the Soft 5 to 6 range, however the larger total, and if it continues into the early afternoon, may push it into the heavy range.
"The bureau generally hedge their bets, but when they say 100 per cent and getting 10 to 25 mils, that's about as solid a forecast as you could possibly get," Kerr told RSN927.
"I think that's a fairly certain thing that we're going to get rain in the morning, but how much is a little bit up in the air.
"We'll keep the fingers crossed that it rains and clears up in the afternoon."
Relying on the rain to have a Good 4 surface to start Saturday's meeting is far from ideal for Kerr and his staff.
But Kerr said there was a couple of options if the forecast alters late on Friday or Saturday morning.
"We can irrigate tonight or if it changes in the morning, we can start some irrigation at 6 o'clock, but the forecast is pretty certain that we'll get some rain," Kerr said.
"The best guess is the rain will arrive around 6 or 7am and rain through until midday.
"How much we get in that six hours, maybe 10-15 mils or more if we get a bit of storm activity.
"If we get that 10-15 mils that puts us into that soft range and we hope we don't get that 25 mils as that may see it a heavy track when they open it up."
Saturday's rail moves back to the true position, the same as it was for last week's Caulfield Guineas meeting, after being pushed out to the 10m range on Wednesday.