Heavy rain and strong to gale force and gusty southwesterly winds will move into Ireland and western Scotland through the early hours of Wednesday morning spreading north-eastwards into Scotland.
A yellow warning remains in place but the storm is not thought to pose a risk to life.
Peak gusts will be just to the south of that across much of Northern Ireland, Scotland, northern England and North Wales.
A Met Office spokesman said Helene could fell a few trees, which could bring disruption to transport links, but did not think it would reach the 70mph winds originally predicted.
Laura Ellam, deputy meteorologist with the Met Office, said: "Throughout this week, we are expecting to see periods of strong winds across parts of the United Kingdom, as well as some heavy rain".
Meanwhile in the USA, the death toll from Storm Florence has risen to 11 after catastrophic flooding hit North Carolina.
"Driving in heavy rain is something that motorists across the country are well practiced in and ultimately it does not appear that Helene will bring weather conditions anywhere near as serious as what parts of the country saw past year with Ophelia".
People have been ordered to evacuate the Carolinas ahead of strong winds and heavy rain as the hurricane lands.
The national forecaster said: "The rest of today will be windy, but winds will moderate away from the south and east coast tonight".
"The winds will gradually ease later on Wednesday, firstly across Northern Ireland, northwest Wales and northern England and then across Scotland".
She said: "Helene is moving up from the Atlantic towards us".