'One-in-100-year' rainfall triggers flash flooding in Geelong and surrounds

Homes and businesses in and around Geelong have been hit by flash flooding as an incredible deluge of heavy rain batters a region west of Melbourne. 

The storm has moved towards Melbourne's northeast, bringing rain across the western and northern suburbs.

Earlier, everal streets in Geelong and surrounding suburbs were flooded, while some cars near the Geelong train station on Fenwick Street were almost completely submerged underwater. 

The Bureau of Meteorology said more than 30mm of rain fell since 9am in Geelong, including 24mm in just 20 minutes before 3.22pm.

In Avalon, west of Melbourne, 62.2mm of rain fell in an hour - double the January average and a figure the Bureau has called a "one in one hundred year event".

The Bureau issued a severe thunderstorm warning for people in Geelong, northern parts of the Bellarine Peninsula, Point Lonsdale, Portsea and Queenscliff.

The Bureau has warned the storms are forecast to affect Laverton, Footscray, Werribee, Melton and St Albans, in Melbourne's west. 

The State Emergency Service received more than 200 calls for help.

A more general severe thunderstorm warning is also current for parts of the Central, Mallee, South West, Northern Country, North Central and Wimmera districts.

For the latest advice and alerts, visit the Bureau of Meteorology’s website.

Do you have photos or video of today's storm? Email them to contact@9news.com.au but please stay safe? 

The State Emergency Service advises that people should: 

* Keep clear of fallen power lines. 

* secure any loose objects in the vicinity of your home. 

* keep away from creeks and drains. 

* do not drive vehicles through flooded areas. 

* stay indoors if possible. 

* Avoid using the phone during the storm. 

* if you are outside, avoid sheltering under trees 

* listen to the radio for storm updates 

* switch off your computer and electrical appliances