Video shot on Jersey shows huge downpours on the island.
Up to 1.6in (40mm) of rain is predicted in some areas, and Met Office forecaster Simon Partridge warned of localised flooding if drains become blocked with leaves blown off trees by the high winds.
One unlucky car-owner woke up to this this morning.
“This will be a bit of a shock to the system for most people in terms of wind and rainfall.
But forecasters predicted the storm will move off quite quickly into the North Sea towards Europe, with conditions set to improve from around midday Sunday.
However, further wind and rain, which is expected to move north across England and Wales on Monday, could bring more flooding, reports the Press Association.
Northern areas can expect more chilly weather with fairly light winds and clear skies.
Drivers crossing the Pennines were confronted with a covering of snow at high levels but all main routes remained open.
Winter wonderland scenes greeted walkers above 1,000ft (305m) in areas of the Peak District and the Yorkshire Dales, with some light snow showers hitting lower ground in West Yorkshire.
Braemar in Aberdeenshire dropped to -8C (17.6F) on Friday night, with sheltered areas in Scotland set to plummet as low as -10C (14F) overnight Saturday and into Sunday morning.
Anyone experiencing problems with their power network during the storm can contact 105 for further information and advice, or visit powercut105.com.