It's wet, it's wild and it will most likely stay that way in Sydney for most of the week.

The Bureau of Meteorology (BoM) predicts up to 20mm of rain will fall in Sydney today, with warnings of dangerous surf conditions.

A water spout off Avoca. Credit:Channel Seven

Photos have been captured of water spouts off the central coast, with Weatherzone saying the coast from Wollongong to Gosford has had its heaviest rain of the month, receiving between 20mm and 40mm in the past 24 hours.

There is also a strong wind warning for waters between Port Macquarie and Port Hacking, in Sydney's south, with a swell of up to three metres predicted.