If you're going back to work today, you might want to grab your raincoat, with London expected to have a forecast of heavy rain. 

As the Met Office has predicted 21 hours of rain in one day across the region, with expectations of potential travel chaos and flooding in some areas. 

The warning comes as the national weather forecaster expected a 'wet and windy' start to the new year with rain starting at 9am on Tuesday, January 3 and lasting until the early hours of Wednesday, January 4. 

The heaviest downpour of the day is expected to arrive between 6pm and 9pm with the wind also set to be strong, with wind gusts of 37 mph coming from the South West. 

East London Advertiser:

With heavy rain forecast, there are warnings to be cautious when travelling, urging drivers to slow down and be aware of their surroundings. 

A Met Office spokesperson said that it will be "largely cloudy at first with rain in western parts soon reaching all areas. This rain will be heavy at times and will continue on and off for the rest of the day. Maximum temperature 12 °C."

What will the weather be like in London this week? 

In London this week you can expect a mix of heavy rainfall to light over cast days. 

With much of the week expected to clear off and have an average temperature of 12C throughout the days. 

Towards the end of the week, there may even be a slight chance of sunshine, with the clouds breaking during mid-day. 

However, the weekend will see a turn, with Saturday, January 7 expected to be dark clouds in the early morning and heavy downpours. 

But it is set to clear off later in the day with slightly less chance of rain in the evening. 

Check the weather forecast via the Met Office website.