Sterling Alexiou hopes the Bureau of Meteorology has erred on the conservative side when it comes to predicted rainfall for Sydney this week.

The trainer would love for Sydney's first Saturday meeting of autumn to be run in traditional autumn conditions with Williamsburg to tackle the $1 million Group 1 Randwick Guineas (1600m).

The son of Snitzel excels when the track is rain-affected with all four of his wins having come on wet tracks.

"If he gets a bit of cut in the ground it brings him right into the race," Alexiou, who trains in partnership with Gerald Ryan, said.

"He runs OK on firmish tracks but he just seems to excel, or the others come back to him, on soft tracks."

After a chance of showers on Monday and a clear day Tuesday, the Bureau has predicted 25-plus degree days for the remainder of the week with up to 8mm predicted on Wednesday, up to 4mm on Thursday, 2mm on Friday and 4mm Saturday.

Williamsburg has had four starts on Soft tracks for a win and a second placing, but his six starts on Heavy tracks have generated three Black Type wins and two third placings, one of which came in the Group 1 Champagne Stakes over the Randwick Guineas course.

He hasn't run a place from three attempts on Good tracks, but he did finish fourth in the Group 2 Hobartville Stakes (1400m) at his most recent appearance and Alexiou has been pleased with his progression.

Williamsburg was beaten two lengths by Osipenko, which was an improvement on his first-up seventh placing in the Group 3 Eskimo Prince Stakes (1200m) won by Aft Cabin.

"That was a big turnaround on his first-up run, which he normally does – he progresses really well off his first-up runs – and I don't think he's going to be very far away," Alexiou said.

"He doesn't have to turn much of a margin around on the Hobartville run the other day.

"I don't think he can be going any better."