The Met Office has issued an Amber Weather Warning for Scotland, Northern Ireland, north of England, and some parts of north Wales.
Wind speeds are expected to reach from 65mph to 75mph, and coastal regions and high grounds may reach 80mph as Storm Ali makes its way to the UK.
The Met Office predicts that winds will gradually decline over Wednesday and a Yellow Rain Warning is in place for parts of England and Wales on Thursday.
Storm Ali is the first storm of the 2018/19 storm season.
Chief forecaster Laura Paterson said: “Storm Ali is expected to bring a spell of very strong winds to northern parts of the UK through Wednesday, particularly Northern Ireland, central and southern Scotland and the far northwest of England. As this is the first spell of very strong winds of the season, and given that most trees are still in full leaf, we are likely to see some dangerous conditions with falling trees and flying branches and other debris likely. Strong winds will be accompanied by heavy, squally showers.”
There are wind and rain conditions expected for the weekend.