This afternoon's Melbourne Cup is expected to be on the slower side due to forecast rain.

Up to 40 millimetres is expected to fall at Flemington through the day.

New Zealand and Australia Racing Hall of Famer Bret Thomson says Flemington is good at draining water, but expects racing to be slow.

He told Mike Hosking it will be a very open race.

Thomson says many of the horses are European, and they tend to handle the soft track well. 

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