The Environment Agency is urging people along the south coast of England, particularly between Dorset and Kent, to be vigilant and prepared for the risk of flash flooding this afternoon and evening (Wednesday).
Between 20 and 30 mm of rain is forecast, with totals of 50mm (almost a month's worth of rain) possible in just a few hours.
There is increasing likelihood of localised surface water flooding, and possible river flooding from smaller fast responding rivers.
There is also a risk of flooding from rising groundwater across parts of Wiltshire, Somerset and West Dorset, including Salisbury Plain.
In Somerset, heavy rain this morning has caused flash flooding in Shepton Mallet, when up to 30mm of rain fell in two hours.
The Environment Agency has deployed pumps to the area.
Flooding from surface water happens when the local drainage system cannot cope with rainfall. It is extremely difficult to predict precisely where surface water flooding will happen as it depends on ground levels, the amount of rainfall, and the local drainage network.
Craig Woolhouse, Head of Flood Incident Management said, 'We have experienced some severe weather in recent weeks and the risk of flooding remains high across England, but particularly along the South Coast of England this afternoon and evening.
'The combination of saturated land, high river levels and further forecasts of deluges of rain mean people must remain vigilant. The public should check local weather forecasts, and the Environment Agency website for information on a regular basis as flooding can happen very quickly.'
Environment Agency teams have been mobilised across the country to check on flood defences, clear any river blockages and closely monitor river levels. These teams have been working around the clock to reduce the risk of flooding, and will be out in force again over the coming days.
Keep in touch
The Environment Agency updates its flood guidance every 15 minutes on its website, and you can follow the Environment Agency on Twitter at @EnvAgency.
Met Office weather forecasts and warnings can be found on its website and you can follow the Met Office on Twitter at @metoffice and Facebook.