Flood warnings requiring residents to take immediate action have been issued in Somerset this morning.
The Environment Agency says water levels are rising following torrential overnight rain and flooding is expected.
It follows a severe weather warning by the Met Office – the most serious alert it can give – and the forecast of further downpours today.
Up to 40mm of rain an hour is battering parts of the region in fast-moving storms.
Weather experts say up to 100mm could fall in places across the South West today, causing flash floods.
Traffic and travel is expected to be severely disrupted, along with outdoor activities planned during the weekend.
As of 12pm, the Environment Agency issued 38 "red" flood warnings in the region, including three in Somerset, which mean flooding is expected and immediate action is required, as well as 32 "amber" flood alerts.
The Somerset flood warnings are at Stoford and Barwick Streams at Stoford and Barwick; the River Tone (lower) from Bishops Hull to North Curry; and the River Isle from Chard Reservoir to Hambridge.
Several roads in the county have already been flooded.
Drivers face delays on the A358 in Ilminster which is blocked between the Crow Lane and Thorndun Park Drive junctions.
Railway services have also been hit, following flooding in Crewkerne and a landslip near Honiton in Devon.
No trains are running between Yeovil Junction and Exeter St Davids, and atrocious conditions on the roads mean there are no replacement buses for passengers between the stations.
South West Trains is advising passengers not to travel on that route unless absolutely necessary.
The operator says tickets for travel today will be valid tomorrow.
The B3168 at Ilford is just about passable at the Ilford Bridges junction, while flooding has also affected the B3168 Station Road at Ilminster near West Street.
The Met Office's red warning doesn't include Somerset, but its amber warning covers much of the county.
Of Saturday's rain, it said: "Although not all places will see the heaviest of the rain, where it does fall it is likely to lead to surface water flooding and some disruption to travel.
"There remains some uncertainty in the location of the heaviest rainfall, but at this time the south west of England looks the most likely area to see the greatest impacts, in particular, the red warning area.
"The public should be prepared for the likelihood of surface water flooding and some disruption to travel and outdoor activities, particularly in the amber warning area."
The severe weather warning is expected to remain in place for the South West until at least 6pm on Saturday evening.