Storm Boelo has brought gusts of more than 70mph (113kph) to the east coast of Northern Ireland, with conditions due to worsen later.
An amber warning covering parts of counties Antrim and Derry comes into force at 21:00 BST until 10:00 GMT on Sunday with gusts of about 80mph or more forecast in exposed areas.
A number of flights to and from Belfast City Airport and Dublin Airport have been cancelled.
In other developments:
A fallen tree is blocking a lane of the M1 on-slip at Blacks Road. Delays are expected
A fallen tree/branch at Lambeg is affecting some rail services
Speed restrictions have been put in place on all railway lines, with bus substitutes available for some routes. Live train updates here
The strongest winds from Storm Boelo are expected Saturday evening and Sunday morning.
The Met Office says there is a good chance that power cuts may occur in the areas affected by the amber warning.
A less severe yellow weather warning is in place across Northern Ireland from 10:00 BST on Saturday until 12:00 GMT on Sunday.
What has been cancelled?
Republic of Ireland warnings
The storm has caused a number of road closures in the Republic of Ireland
As of 17:30, more than 18,000 homes are without power
An orange wind warning is in place for counties Donegal, Galway, Leitrim, Mayo and Sligo from 14:00 on Saturday until 09:00 on Sunday
A less severe yellow wind warning covering Connacht, Clare, Kerry and Limerick took effect at 13:00 on Saturday and will remain in place until 12:00 on Sunday
A separate yellow wind warning for County Donegal is in place and will run until 15:00 on Sunday