Revellers heading to Sydney for Saturday's Mardi Gras celebrations no longer face the prospect of wild weather despite wet conditions, according to the Bureau of Meteorology's latest update.

The bureau's 9:48am update on Saturday cancelled a severe weather warning for Sydney, the Hunter and the Central Tablelands advising residents to brace for heavy rain, thunderstorms and possible flash flooding along parts of the coast.

The warning remains in place for people in the South Coast and parts of the Illawarra, Southern Tablelands and Snowy Mountains districts.

Areas of the Illawarra and South Coast have recorded falls of more than 100mm over the past 24 hours as a low pressure system off the state's central coast drifts south and southeast.