The forecaster has warned of winds of up to 70mph this weekend.
The yellow alert is in place from 7am this morning, with another alert issued for tomorrow.
People have been warned it could affect Christmas travel plans.
A number of ferries have been cancelled today and tomorrow.
Watch: NI Travellers arrive home for Christmas
A fallen tree partially blocked the inner lane of the Knock Road at the PSNI HQ in the direction of the Upper Newtownards Road in Belfast. It has since been cleared.
P&O Ferries announced a 24-stoppage between Larne and Cairnryan.
It said: “Due to adverse weather conditions, all P&O Ferries sailings between Larne and Cairnryan have been cancelled from 8pm tonight (December 21) until at least 8pm tomorrow night (December 22).
“We ask our customers please not to travel to either of the ports if their sailing has been cancelled, to avoid causing traffic congestion.”
“All remaining sailings for today are fully booked, customers can manage their booking online or call us on 01304 884488 to amend or cancel their booking. We apologise for the inconvenience.”
Stena Line have also said disruption is expected with sailings between Belfast and Cairnryan cancelled late on Saturday and into Sunday.
The Met Office said “Strong westerly winds are expected to develop through the course of Saturday, with gusts of 50-60mph developing quite widely across this region, and a small chance of gusts reaching 70mph around some coasts and high ground areas.
“This has the potential to cause delays to public transport and some disruption to the road network, which may have a greater than usual impact given the busier pre-Christmas weekend travel.
“Dangerous coastal conditions can be expected too, with large waves an additional hazard.”
Today’s warning is in place for counties Antrim, Down, Fermanagh, Londonderry and Tyrone.
It also affects Scotland and northern parts of England and Wales.
Meanwhile, a second alert is in place for Northern Ireland on Sunday, amid warnings of prolonged strong winds.
The Met Office added: “Strong and gusty northwesterly winds are expected to develop on Sunday.
“Gusts of 50-60mph are expected quite widely, and around some exposed coasts and hills of gusts 70mph are possible, especially in the north and west.
“In addition, squally showers are likely with some hail and thunder possible in places.”
The alert is in place for all six of Northern Ireland’s counties, running until 9pm tomorrow.
In the Republic of Ireland, a two-day yellow warning has been issued for eight counties.
The alert for counties Donegal, Galway, Leitrim, Mayo, and Sligo lasts from 3am on Saturday until 2pm on Sunday.
A separate alert for Clare, Kerry, Limerick lasts from 3am on Saturday until 3pm on Sunday.