An afternoon storm in Sydney has put the Rosehill track into the heavy range on the eve of the Expressway Stakes meeting.
Further rain and thunderstorms are predicted on Friday evening and Saturday.
Noted wet-track performer Tiger Tees has firmed from $15 to $10 with the TAB for the Group Two Expressway (1200m) with Our Boy Malachi the $2.40 favourite.
The Joe Pride-trained Tiger Tees is having his first start since being unplaced in the Group One Darley Classic in the spring in which his brother Terravista finished third.
The winner of the 2014 Group One Galaxy (1100m), Tiger Tees tuned up for his Expressway assignment with a barrier trial at Hawkesbury earlier this month.
"Tiger Tees is well and the rain helps him," Pride said.
"He's got form on firmer tracks but he prefers it with give in it."
The meeting also features the first stakes races for two-year-olds for the year with 13 fillies accepted for the Widden Stakes and the eight colts and geldings in the Canonbury Stakes.