A fierce storm knocked out power for hundreds of thousands of people in Ireland and threatened to disrupt travel across Britain on Friday, one last punch from a weather pattern that has already delivered bitter cold and record-breaking snow to parts of the United States.

Damaging gales from the storm, which is named Eowyn, are expected throughout Friday, with the strongest winds forecast for parts of Northern Ireland, southern Scotland, and northern and western areas of England and Wales. Wind gusts between 60 and 70 miles per hour are forecast, and gusts of up to 100 miles per hour are possible around the hills and coasts of the Irish Sea as well as southwest Scotland.

Some forecast models suggested gusts up to 120 m.p.h. for the west coast of the Republic of Ireland, equivalent to the sustained wind speeds of a Category 3 hurricane.

By early Friday, the storm had already brought record winds to the Irish coast. At 5 a.m., a gust of 114 miles per hour was recorded at Mace Head, County Galway, beating a previous national record of 113 m.p.h. set in 1945.

The winds have been so strong that they have apparently disrupted some efforts to report them: “Severe winds have interrupted data supply from our stations in Belmullet, Mace Head and Markree,” Met Eireann, the Irish weather service, said on social media.

ESB Networks, a state-owned power company, said Friday morning that “extreme, damaging and destructive” winds had caused widespread disruption to Ireland’s electricity network.