Strong winds and heavy rain have battered many parts of the country - and forecasters warn there is more on the way.
Gusts of more than 50mph were recorded in Cornwall as the storm roared in from the Atlantic.
Rain affected many areas and the first day of the Third Test between England and the West Indies at Edgbaston was confirmed as a washout just before tea.
Chris Burton, a forecaster with MeteoGroup, the weather division of the Press Association, said: "We may see gusts approaching 70mph on exposed coasts and headlands in south-west England and in south Wales.
"We've already had a gust of 57mph at Culdrose in Cornwall at about 3pm today.
"There is a deep area of low pressure to the south-west of the UK, deep for this time of year, and it's going to track north-east through the afternoon and night."
Through tonight and Friday, the centre of the storm is expected to move slowly north-east, touching areas as far away as north Wales and exiting Britain as far north as Northumberland.
The Met Office has warned of strong winds expected in south-west England, particularly Devon and Cornwall, and also sounded an alert over heavy rain today across southern parts of Northern Ireland.
On Friday, Met Office warnings over wind and rain are extended to include south Wales and many parts of southern England as well as the South West.
Spokesman Charlie Powell said: "It is possible there could be up to three inches of rain in hilly and mountainous areas of Wales, with lower but still substantial rainfall in more low-lying areas."